I'm sorry for this but this needs to be said.
TL;DR
As it currently stands, Tekken 8 is a bad game. It is ABSOLUTELY not worth ANY cent right now. Not even a -insert pirate skull here-. It is yet another MK1 situation all over again where hack developers like Namco Bandai are being tone deaf on fixing their game.

Pros-
Core gameplay is fun, casually
Solid music. Jukebox is not PS exclusive anymore
Outstanding visuals & spectacle
Online rematches don't require you to go through a stupid loading screen mp4. anymore

Cons-
Mediocre story campaign with a dishonest, gaslight-y "redemption" of Jin's character
Garbage character episodes... again
The most inconsistently performance optimization in a fighting game yet
No way to turn off upscaling so the game will always look like some form of dogwater
No Benchmark test for online (no, the stupid nothingburger that gives you a numbered score is not a benchmark test...)
Abysmal character balance
Adding an Electronic Fart MTX Shop and later a Fartnite Battle Pass on this $70 game a month after release and it's just as terrible as SF6 due to the game forcing your to overspend to afford one item.

and the big one. The online & mechanics. The former is just as bad as SF5's & KOF XV's
Netcode is inconsistent at best. 5 bar ethernet matches 8 times out of 10 randomly fluctuate down to 4, causing teleporting.
Wifi matches are still a chore as usual.
Quick matches are still limited to best of 2 for no f^c&ing reason
And probably the worst ranking system in the entire franchise, if not, all fighting games because of one simple issue.
There's literally ZERO point loss penalty to rage quitting/plugging. (fun fact: T7 forces the quitter to lose points and rank while this game doesn't) What this means is that any garbage sore loser player that refuses to hold an L can easily reach God of Destruction by hitting ALT+F4 before they lose with NO consequences at all. LowTierGod can easily get GoD rank if he really went 1% more than 2... What a joke. Bad enough that the game takes far less skill than even T7.

The gameplay is fun like I said before, but competitively it is a sad pathetic joke... Tekken 8 at it's core is fundamentally flawed to hell. Heat had tons of potential to make Tekken more fast paced, but in execution it's a very badly designed mechanic that forces the game to be a 50/50 panic/guess simulator due to it 95% of the time always being plus on block along with returning ♥♥♥♥♥♥ Rage Arts and annoying ass Power Crushes. All culminating into an even more aggressively shallow "Tekken 7" that has rules that are instantaneously contradicted by said mechanics while also dumbing the game down in a terrible way. To call it bad game design is an extreme understatement. The skill gap isn't even lowered here, it's just nonexistent which is worse.
That's just the mechanics, the core game itself is just bad. It being Vanilla is not an excuse for it having...

more inconsistent hit detection than T7
Throws being 100% trackable so sidesteps are useless
Excremental Ranking system
Fecal Netcode
Random server crashes
Broken skill-based matchmaking
Insanely convoluted "Prowess" system
Input Eating
No infinite rematches in Quick Match
Diabolical character balancing and oversimplified changes. Law & Eddy are 2 main examples.

This is a glorified early access build disguised as a "finished" full priced game. It's kcufed. It is really cathartic to see more and more people calling out this dry @$$ shallow kiddie pool of a Tekken. If this game wasn't called TEKKEN & it was sold as a new IP, nobody would give a s#%! just like DNF Duel. And of course there will still be a group of people that will defend Namco for life. To those people, I say this. Tekken 8 costs $70 There's absolutely no excuse for any of this. There's a reason I bought this second handed, cheap. Because I refuse to support garbage like this with my wallet, no matter how much I love Tekken. Bandai Namco are dishonest and tone deaf on fixing these obvious issues and are prioritizing polishing their new MTX shop & Battle Pass instead. (even they screw that up. there's a clip on twitter on which the shop has a game breaking bug where the outfit you brought doesn't even work in the customization menu LMFAO!!!)

TTYTT, Tekken ever since 7 has been a sad joke in my opinion. There is still fun to be had, but not worth having to deal with all of it's disgusting issues that the devs refuse to fix... This will definitely be my last Tekken game. Tekken 9 will be just as bad if not worse as long as there are still Tekken Stans that keep trying to excuse & justify everything Namco, Harada, Murray, etc. The constant free pass that Tekken gets on a yearly/hourly/daily basis out of all fighting games need to stop. Y'all are better than this.

My advice. Don't waste your $70 and wait about 4-5 years from now. Or at the very least get it on a very cheap discount.
If all of these issues especially the mechanics are not completely fixed for the rest of this year or even it's first anniversary, The King of Iron Fist Tournament 8 will not make it to season 3, Period. This has got to be the most disappointing game I've ever played in my entire life...

Honest Thoughts: This is damn fine game for newcomers of the series, even longtime fans as well. But for me as a hardcore R&C fan, while I genuinely did enjoy this new entry from start to finish with it's sound design, the feel of certain weapons during gunplay, & the amazing KB/M support, there are so many disappointing aspects of the game that weigh it down hard for me.
The extremely average plot & writing, not that many planets, not enough platforming, lacking enemy variety, terribly recycled boss fights, excessive dialogue every 3 seconds, sometimes bad voice direction, extremely forgettable soundtrack, Ratchet's character being so damn bland, Rivet & Kit's conflict feeling rushed, overly childish humor & dialogue, even that one part on Savali 2 where Clank swears, feels extremely forced instead of funny to me, & overhyped rift traversal setpieces which are literally just spectacle and nothing else.

In my opinion, if you can get this game under $60 on a sale like I did, this is a very solid game for longtime fans of the series. Just do not expect this to be evolution of the franchise with an engaging story with complex levels & lite-PG-13 wit from the older games, otherwise you WILL be disappointed like I did back when I watched youtube videos on this game back in 2021.