I think this applies to many different creatures, not just the mana. Titans, upon release, dominated extinction. Undeniably. And it made sense for the gigantic titans to dominate the world. I play both PVE and PVP, and in PVP, I see these enormous, apex predators able to be taken down by any tribe with 4-5 meks. Which is more balanced in general, but when it simply doesn't make sense. The way ARK has always functioned was : Big Monster = Big Threat. The titans no longer adhere to this logical rule. Now, on my PVE world, I have a level 301, health and damage mutated Giganotosaurus. It is about as strong as my level 290 Rex. See the stupidity here? The Giga is roughly 3x the Rex's size, but a higher level, mutated Giga is weaker than your average damage-focused rex. I, of course, remember how OP the Giga was in PVP when it was first released. But I do NOT remember it making PVE less fun, or unbalanced for new players. In fact, the Giga nerfs were DISAPPOINTING in PVE. Like any sane man, I am afraid of wild Gigas. When I first ever tamed a Giga, the nerf was out, but I wasn't aware of this. I was expecting a massive beast of endless might, but I just wasted a lot of tranqs and meat.
TL;DR
PVP nerfs are slowly ruining the PVE experience, and I have seen it firsthand.