To be honest, yeah, these games have their flaws, especially in the optimization department. HOWEVER, that hasn't stopped me from really liking these games.
I personally find the story to be really nice, a lot more enjoyable than Sword and Shield's (though tbh I liked those games too), and the Terrastalization mechanic makes me think of 'Mega Evolution but your type matters more than ever', you know?
So, if you ask me, it's all down to personal preference.
If you wanna get the game (or both, if you're wildin') then go nuts, it's fun!
If not, then maybe wait for a sale before you try it.
It's one of those cases where you can't really knock it until you try it, and if you don't like it, then that's your opinion.
EDIT: I finished the game a few days ago. I'm changing my score to 5 stars solely due to the story the game has, holy hell what a ride.
Thanks for bothering to read this whole review, have a great rest of your day.