What is Scizor? What is Houndoom? What is Crobat? What is Tyranitar? What is Heracross? What are the starters? Like yeah I get the 2nd gen is not as beloved by the Japanese but let's face facts: BW Era were basically transitional/soft reboot for the series' lore for XY, which is literally RB done over. Of course while SM is the sequel or spiritual successors to XY they can't just keep slamming megas when it's such a volatile time for them. Half the community, especially "big wigs" hate their guts and bitch all the time about them now, the other half understand that times change and while some Megas weren't too great, the majority of them made unpopular mons, like Mawile or Houndoom or more so Manectric, popular. Legit they would be stupid after this whole 20th anniversary bonaza bullshit not to keep pumping out Megas, cause at the end of the day while we have Alolan Variants for 1st Gen mons, doesn't mean they could do all of them. While they have specific Z-Moves, does not mean they could come up with finisher moves for every single pokemon, well not off the top of their heads. The points is Z-Moves were meant to be like an Anti-God Weapon, like excalibur or brionac, for Megas. It's also at this time they are editing the Megas so they fit into the Meta better so it isn't as much of a need to have one.
Hell real talk, if anything they should keep Lando-T, Cresseila, Heatran and those mons banned until there are fully effective, not as obscure cause people bitch, ways to deal with them. Sucks for Zapdos and the first four sets of sub-legendaries but due to how powerful Lando-T is alone THAT's what they should find a way to nerf. And yes yes I know what is water or ice pokemon but it's been top three on battlespot for a reason.