Bayo 1 has better combat system with it being more intricate and balance but as a game to play through Bayo 2 is better as it fixes a number of questionable design choices in the first game, as a high level player the are examples of issues in both games.
The are certain things combat in Bayo 2 doesn't allow due to changes in the combat because of the focus of WT as a central mechanic but as a game it's better by far as it has better structure, mission types removes QTEs, gets rid of stage hazards (burning ground etc...) and reduces the number of horrid on rail missions. An example of what I mean is the After Burner stage in Bayo 1 it is a long winded on rails slog that you always have to playthrough to get to one of the best boss fights in the game the two sections should have just been made two separate missions as if you're going for pure platinum runs you really see the flaws in the game's structure especially with the unpredictability of boss fights. Bayo 1 has some of the best bosses but what holds them back is BS like mid battle QTEs that are instant death and this again is present in the said mission because you can be in the midst of a combo and set up then the QTE comes and in the original versions of B1 they were more random in the buttons to be pressed and this could mean that in split seconds a platinum or pure platinum run of a mission would die and the whole mission would have to be done again which is why the mentioned mission is the perfect example of the flaws in the game. Compare this to DMC games where the battle is just you, your skill and the boss with no interruptions.
On the flipside B2's changes in combat are what are the main issues for it the reliance on WT as a central focal point puts restrictions on combat for example in B2 you cannot launch mid to larger enemies into the air with out it anymore and various mechanics were nerfed with no balance applied to them such as the parry and weave attacks. In B1 when you perfect parried you activated extended WT while in B2 the game where WT is central you get no such reward in combat for perfect parries making it pointless even having them. In B1 weave attacks were powerful in not just damage output but in staggering, launching and disrupting enemies but in B2 they don't do any of that due to being nerfed and WT being required to to stagger, launch or disrupt mid to large enemies yet in the game they still consume the same large amount of magic as they did in the first which makes them pointless and just pushes the player to only use climax with their magic instead. Another issue is due to WT being made more central to combat some enemies are only really vulnerable when it's active even if you activate climax they can still parry or evade your attacks no matter your skill which forces the player to use certain approaches in battles were such enemies are present.
Between the two due to the flaws they're about even overall but if you're looking for high level combat B1 is better if you're looking for an action game to play through B2 is better.
