I use a different email address for each account thanks to anonaddy.com or simplelogin.com. They all forward to my private Proton account. Few people or companies know my real email address which makes it impossible for the data vultures to correlate or identify me. The + deliminator won’t protect you much as that is simple for brokers to parse.

It is basically marketing. GAFAM spends billions on it in partnerships, favorable articles, advertising, and lobbying. FOSS relies on us to evangelize to our friends and family.