I have used the company-i-buy-from in my email address I give the for over 20 years. It mostly works well, a couple of serious businesses had their data stolen and are now blocked and I use a secondary address for them if I still have a need. Never noticed a spammer would misuse the scheme, even though it would be extremely easy.

The funniest experience was when searching a VoIP provider. One had it in their terms that their name must not be part of the email address. Well, no chance to get my business then.