>>57993312 (OP)The only negative is that if you catch a pokemon there's a 95% chance it's tera type is just it's first typing, and that's pretty much because they needed a reason to do tera raids and gathering tera crystals. I can see the reverse where the tera type being random could suck ass, but catching a fire type and knowing it's tera type is going to be fire is just incredibly boring.
But just like mega stones mostly being post game, or z-crystals being spread throughout the game, or even pokemon not having the ability to gigantamax because once again they wanted you to do raids... none of that is about the mechanic itself.