I know its effecitvely a vendor lock-in and not what you are looking for but I love the SimpleLogin integration that Proton made with Proton Pass.

I have it setup in my browser and phone. Whenever a website or app would like an email for an order or something else, it takes a single click to generate a named alias (using the website name) e Which forwards emails to my normal inbox. Replying to any received emails also uses the alias.

The SimpleLogin interface could use some improvement though. Deleting unused ones is a bit tidious.

I use SimpleLogin with custom domains but kinda meh.

Brilliant for quick creation of temporary emails, but app troublesome and doesn't show the all options, but much to my disappointment they don't do proper SRS, so it invalidates any, ANY benefits from DMARC or such.

Emails that with SRS would have a proper From, organisation logo from BIMI record, now immediately end up in Spam and are marked as phishing attempts.

I had a better success with personal postfix server forwarding my catch-all alias mail to Gmail than I have with SimpleLogin.

The only thing that is better is that replying to emails is easier, but that could be done while staying compliant with SRS.

I regret buying the subscription and I won't be extending it. Should've go with a proper email service, not a glorified alias generator.