This game gatekeeping you with side quests to progress the main story is the equivalent as being told you can't go outside till you do some extra homework.
The story and battle system Torna has to offer is incredibly interesting, and I won't lie when I say the moments with Lora, Gin, and Mythra were very interesting - but it's all heavily guarded by side quests. You're told twice in the main game, but most notably just before the finale - that you should help the people of Torna, and you're actively forced out of story progress until you do.
It's horrible artificial padding, and it honestly didn't feel rewarding at a point because not much changed when you did them. I personally ended up skipping most of the enemies later on because the forced side quests kept me at a decent level anyway, and by then I was getting sick of the battle system.
I'm not saying Torna is bad by any means, but I am saying it has its heavy faults. You will still find plenty of joy in this package, however with Future Redeemed doing what Torna did wrong and fixing it - I think I can safely say in hindsight that this was Monolith testing the waters with Xenoblade Expansions, and I'm glad that the blunders in this campaign meant that the devs could learn from their mistakes and make side content actually worth exploring and doing in Future Redeemed.