>>58159276Gamefreak reduced their value the same generation they removed the mechanic and introduced new alternate Gigantamax forms for Pokemon that already have Megas
Since it's up to GF to decide when Megas will come back, stuff like Mawile and Aerodactyl are effectively held hostage and stuck with low stats in the games where Mega isn't a thing since we're not likely to see actual evolutions to them anymore.
I feel the same way about regional forms. Stuff like Sandslash, Marowak and Ninetales get absolutely nothing, but here's a regional form that's completely superior to the original. Then you have Linoone and Mr. Mime whose regional form is the one to get a fucking next stage evolution.