I agree that the pure fullback position has been phased out of today's game, much like how wingbacks are no longer used, etc. The last time we actually used a genuine, honest to goodness, classical fullback was when Aasaph Schwap was here (God rest that behemoth's soul).
That being said, using TE's as H-backs isn't a new idea, and works quite well in today's game.
Tommy Tremble did a very fine job as a H-back in 2020, and helped pave the way for many of Kyren Williams' runs. That, plus it gave Chris Tyree another blocker to follow. It was no surprise that he took fewer hard hits at the line of scrimmage as a result of having Tommy Tremble in there to lead block for him.