>>52447227Let me describe a hypothetical scenario, I realize this is IS hypothetical in the first place and other turns before it could have influenced or made this situation I'm going to sketch avoidable or something you can position around, but for the argument I think having a scenario like this helps explain what most people dislike about the mechanic. There'll be some reddit spacing for readability.
Endgame, last mon situation. Kingambit on player A side, Cien-Pao on player B side. Cien-Pao has Ice Spinner, Sacred Sword and Crunch. It having crunch wouldn't (or sucker punch, sd or whatever) actually matter normally but I just put it down for the sake of it.
Player A has not revealed their tera yet, meaning it is very Kingambit is the intended user (it is the last mon), thus it is predictable ..but it isn't forced to. In any other generation Player B would have won here assuming it's out of (crit) Sucker Punch range, it clicks Sacred Sword and it wins. In gen 9 however, this is a raw guess. Kingambit's often run Tera Flying, Fighting or some other weakness covering move. If it's flying, Cien-Pao CAN still win by clicking Ice Spinner, however if player A does not Terastalize, it will lose doing that. If player A stays in it's regular typing it will lose to Sacred Sword, but again it can change. And ultimately not even limited to changing to flying or whatever, it has options. These ARE coin flips.
I get this migth sound like a convoluted example to make terastallization seem more broken than it is but it's based on a situations that are happening quite often on the ladder right now, and in the no johns 1000$ tournament on Smogon right now. I'm currently not behind my PC but once I am I can dump casually dump over a dozen replays with tournament level players where the endgame is almost entirely decided by a terastallization coinflip like this.