A vast majority of the defense for these changes has been: "It's optional, just don't do it". That's not really true in all cases, and for the 100% optional things then I don't care. However, some of these changes drastically alter the balance of the game and that is not optional. Here were the original points:
1) Respec at will.
2) Respec companions.
3) Removed ability score requirements for multiclassing.
4) Giving all the good parts of multiclassing with no downsides (i.e. getting fireball the same character level as a single class wizard on a multiclassed character)
1 and 2, I don't care about. Those actually are optional. Go nuts if you want.
3 will slightly change the balance of the game as now you're able to create builds with ability scores that weren't possible before. I don't think it will be too big though, so it isn't the end of the world. Although I don't want to completely discount it without looking into it more deeply.
4 is a massive problem and that is the issue that needs to be resolved. It completely nerfs single class play, and the game won't be balanced around the worst possible build you could make. You want to be a single class wizard? Well good luck, as every other wizard gets all the same spells as you and also has armor proficiency, plus other subclass features with 0 downside.
+1 The biggest problems are in 3 and 4.
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