>>56789386Because they completely gave up on making it something you'll find any challenge with thanks to the existence of minmaxed "not a legendary but basically as powerful as one" species like Ultra Beasts that only (You) get to use (but they didn't see any reason in banning them because they don't meet the arbitrary criteria of "strong enough" despite said minmaxing) and in SWSH they outright allowed you to use Pokemon that would normally be banned, meaning Zacian could unga bunga the whole thing brainlessly.
Paradoxes, including the Raidons, would've no doubt created the exact same problem if SV had a Battle Tower.
Or, the shorter and real answer, why bother implementing the Battle Tower when you can just tell people to buy a NSO Subscription and play PVP endlessly until the next generation? That's basically the same thing if not better because now you're fighting actual opponents and not garbage AI that has to teambuild specifically to counter (You) and rig RNG to beat you, right?