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.
D&D has been committed to Polytheism long, long before this, that is not new.
That being said there is nothing mechanically that forces you to make home brew settings polytheistic, but you can home brew monotheistic settings too