I pay for the subscription and if I didn’t I do not mind free services asking for money. If you are giving me a free service and not data mining me then you have every right to nag me.
Gmail litterally puts ads in your inbox that look like emails so I doubt any service is gonna be worse than that.
The CEO of PROTON answers YOUR questions! Drive, Linux support, Photos, features, and a lot more! (tilvids.com)