I disagree that it makes the game easier. Yes, it allows players (say in the FE) to gain a (for example) Champion's retreat from the PME. But it isn't making it easier to do this - instead it's creating a way to do it. It's not removing obstacles and giving us a shortcut - it's giving us the chance to do it at all.
there are buildings players can't get anymore
like the Speakers Corner or Mad Scientists Lab
if someone doesn't have it: bad luck
if you didn't win a PME champions retreat: bad luck for you
but you can still play the game and take part in PME GvG with other units
so where is the idea to give players the opportunity to get the Speakers Corner or Mad Scientists Lab who didn't got it in the past
btw: I can do the same things without champions of a specific era.
so if you can't do it and need champions because you can't do it with other units of that era that would make the game easier for you