Why would anyone use this over Proton Mail or the gazillion alternatives if it treats people like shit.
Yes it is. It is malware at this point. (It’s trying to trick you into clicking ads.) If I can invite you to try Port87, it’s an email service that I wrote that does the opposite. (Keeps spam out of your inbox, rather than inserting spam into it.)
Full disclosure: I developed and run Port87, and as such, have a financial interest in it.