I personally use aliases for banking, health related services, online shops, academic and professional accounts, and government related ones.
So it’s basically what you described except I added health and online shops.
The reasons I did this are :
- Sorting mails work better with aliases routed to specific folders rather than traditionnal filters (at least in my experience and with the client I’m using for all this stuff).
- If there is a data breach (and the main email related to these aliases actually suffered from 8 different data breaches since 2008 according to Have I Been Pwned, including 4 just last year), at least it’s localized to only one area of your life and since you might not have the same data stored everywhere, you will reveal less information.
- My main email was my first and last name, so with aliases I could at least hide it a little to have extra privacy/safety.
I think this is a healthy strategy that is not too difficult to set up. I’ll probably set something similar for my parents and my sister to help them sort out their mails better (and reduce spam a little since it also helps in that regard).
I also use Proton on the side with nothing related to my real name, and also use aliases to sort out mails as well as having throwable aliases for one shot accounts, but that’s outside the scope of your question.