The designers made an effort to make the eladrin elves an overtly ‘magical people’. If this kind of elf is Charisma-Intelligence, then the mechanics will match the flavor, and I will be happy, no matter what.
Feystep/Mistystep guarantees the eladrin will be mechanically viable.
Regarding the D&D Beyond video, my interest is the setting assumptions. I worry that 5e is baking too much setting flavor into the core rules. I prefer core rules of D&D to be setting-agnostic, so that any kind of setting is possible using D&D rules. I personally dislike polytheism, so dislike the ‘great wheel’, so am uneasy about ‘celestial’ mechanics.
In the case of the eladrin, I simply want to understand what the designers are saying about the setting implications.
Crawford said there is more than one origin story − more than one ‘myth’ about the origin of the elves. Unfortunately, he said all of the ‘myths’ have the elves be the ‘offspring of a god’. Thus the D&D brand seems irredeemably committed to polytheism.
Even so, the possibility of multiple ‘myths’, includes the possibility of D&D settings that lack polytheistic gods.
I hope D&D rules support the possibility of settings that dont require the worship of polytheism.