You're complaining about different things than what Tasha stated. To part of your point, there still isn't a guarantee that people will use the new limitation, "even if [the powers] conceptually fit." As for what is or is not allowed in an EC, clear back to 2nd edition it reiterates multiple times that the GM decides what is and isn't allowed in an EC. That's still true in 5E where every time it says, "you can't do this," it immediately follows up with, "unless the GM allows it." [Not direct quotes, but my paraphrase.]
Tasha's statement was that ECs had no "real limitation" as compared to UP and the point total limits of an MP. In 5E, an EC has the same "real limitation" as UP provides in her example. I was merely bringing up an objective fact, not my subjective opinion on ECs.