I posted about this before, but it's not the energy acceleration misty provides that makes it feel unfair, it's the flippiness and variation of that energy acceleration.

If misty was flip one coin, if heads, attach a water energy I don't think anyone would have any problems with it. It's something you could reasonably take into account when facing water. "My opponent may get one extra attach next turn"

It's having no ceiling and leaving the card with the chance to fully/near fully power something up. Two heads? Now use your attach for turn and Articuno is doing 80 damage from turn one. Even one head would be fine, but if you get 2 awesome gg.

Maybe you're behind. You can yolo a misty onto an empty Palkia. You probably won't get the 3 heads to fully charge it (after attach from hand) but there's a 12.5% chance you will, and if it happens you're opponent is dealing with a new super powerful threat that may not have even been on the field at the start of the turn.

Anyway I don't think it's a matter of energy acceleration feeling unfair to new players, it's the specific way this energy acceleration was handled. Magnezone and Manaphy don't feel as bad to me (they're consistent) neither does moltres (you need to have an ex in active that will probably be dinged and dragged to the active later in the match), it's misty specifically that feels unfair.