At the time of writing this I have about 30 hours in the game and have absolutely loved it. Terastallizing feels like an interactive and unique mechanic that will add decisions and variety to your battles instead of being a non decision like mega evolving or being as extremely volatile like Z moves or Dynamaxing. The mechanic, at least so far in singles, is absolutely fantastic in my opinion. Many of the new pokemon fill unique roles and many of them will still have a niche even if there are other pokemon who do similar things. For example the new pokemon Brambleghast and the old pokemon Dhelmise are both the same type and use physical attacks, Dhelmise just has higher health, attack, and defences. But brambleghast has a unique ability that allows it to have much better attack and speed under certain conditions, there are plenty of pokemon like this, and it's very fresh to see pokemon not be completely outclassed on release. The designs of pokemon this generation are absolutely fantastic, I love almost every new design from this generation, and there are some excellent redesigns for pokemon from older games as well.
As long as you are fine with the frame rate being inconsistant and the game not looking up to par with other triple A titles I would absolutely reccomend Pokemon Scarlet and Violet