Many of the objections come from wanting to do things the old way, without privacy and responsible handling of private data.
No, they come from the fact that privacy comes at a cost. In this case, it's much harder to receive support, find your account if you lose it, and get proper communication. Everything is a trade off, and anyone who thinks the reason things have been done this way is only to scoop up as much data as possible is either brainwashed or naive. These changes are adding a whole new layer of complexity, which may be worth it in some cases, but in others it just is a net negative for the customer.
{app_name}@example.com goes to the same place, but it is easy for me to see if they sell/lose my email. And if it gets lost I'm done with them I can just block that specific address.
The added benefit is no one can assume that {my_name}@example.com is my bank email address or my email login.
I used to have a standard {username}@gmail.com for a while, but now it is on 20+ breached site lists. Best case? Copious amounts of spam. Worst case? I may have been reusing a password prior to switching to a password manager.
Now, I can just block the email from receiving anything. Two, if I accidentally reuse a password the username is at least different.