Often do that as well, but then: What’s the point. Company X leaked my mail, so what? Not much that one can do about it. Now I often group services, e.g. car rentals with car@ and food delivery services with pizza@
It’s awesome for filtering and sorting emails though.
You can sometimes remedy the problem. I went through a few aliases with Amazon, and finally found the secret option to keep my email private. (By default, they post it on reviews or something stupid.)
It's especially good for apartment searches and job hunting. Companies that try to link buyer and seller are naturally spammy, so you create a new one for each contact. Then when you find one, you delete the others.
It's also makes it dead easy to filter all that information into folders, so you have a neat record of all your interactions with the various companies you're dealing with.
Most importantly: once you find a job / landlord / whatever, you really want a reliable line of communication. This way, your address with them never changes, but all the spam goes into the bit bucket.
If company X leaks your email, close your account with them and block the address.
Also, it's useful for have i been pwned. One of my few accounts which uses a grouped address is in today's data dump, and it wasn't clear what account it was, because of the grouping.
It’s awesome for filtering and sorting emails though.