No, this is as far from what is actually being said in the pro-tera side as can be and you clearly have not been paying attention to the thread on the in depth discussion of why. Your statement on team building is a double edged sword and shows how little you understand developing meta games as a whole. You can't even make an argument on team building until the meta actually settles down and people decrease the amount of TESTING of various sets. The strain on teambuilding is twofold because both camps, before the match even begins, needs to plan what Tera types work best for their team. You tell me, exactly how different is this from picking items, Iv's/Ev's, and team members? These are all factors you cannot change mid battle. Once I decide to lock in my tera type Dragon Charizard in teambuilder, I can't magically make it a Water type mid battle. This notion of "it can turn into anything so its bad" stems from lack of understanding of the new pokemon, who have only been out for 8 days as of this post. understanding of the new mechanic, and understanding what tera types work better with what Pokemon.I have been trying to argue this exact thing, but majority of the pro-tera arguments apparently are
a) it's fun because unpredictable
b) it's the generational gimmick
And neither consider it's strain on teambuilding. Both arguments are pretty ridiculous and it shows how so many casual players are completely out of touch with the singles 6v6 meta
Of the previous 3 generational gimmicks thus far, only one was banned. Dynamax was on a level far more insane than anything we had seen previously and it was clearly built towards VGC given how the mechanic worked. Mega's and Z-moves both had aspects of prediction not previously seen in the game, and Tera is no different. As it stands, terastilization is the arguably the weakest mechanic of the 4. Like Mega's and Z-moves, you have to plan out what you bring to the fight. The difference is that the mechanic itself doesn't actually give you a net value every time you hit the Terastilize button. Hell, you can even go games without using the mechanic because you never actually had a good time to use it. This is the first mechanic that actually requires thought before use and using it to early can cost you games. When you have enough games under your belt, it becomes far more predictable. And even when you get surprised by a terastilization, that doesn't mean it was a good one.