Yes, that's exactly what plus addresses exist for!
It seems to me like all benefits of the "exact same email, multiple accounts" feature are vastly outweighed by the inconvenience for users simply forgetting that they already have an account, and creating a second one by accident that way.
I mean, even I end up almost creating an account by accident every now and then (mostly on sites using the horrible "signup is the default, login needs one additional click" pattern), and I do so using autofill from a password manager!
It seems to me like all benefits of the "exact same email, multiple accounts" feature are vastly outweighed by the inconvenience for users simply forgetting that they already have an account, and creating a second one by accident that way.
I mean, even I end up almost creating an account by accident every now and then (mostly on sites using the horrible "signup is the default, login needs one additional click" pattern), and I do so using autofill from a password manager!