I'm not an expert on all the technicalities of League but this is a term I've seen going about frequently these last few months. No idea what it is though.
Can someone explain it to me and why the issue should be concerning?
This is how I think of it:
Early champion designs were intended to have significant trade-offs. That is to say, champions who got a lot of mobility tended to lack in some other aspect - damage, utility, etc.
Now, mobility is given in addition to having high damage, utility, etc., which makes many (but not all) old, non-mobile champions comparatively bad.
It's not like many of the older champions aren't still playable, and some that are strictly out of place have been or are being reworked, but there is a tendency for newer champion kits to have a lot more options and power than older kits.
https://www.youtube.com/watch?v=Bxszx60ZwGw Substitute "Power" with "Mobility" and that's your answear.
