Yeah, I don't see a point in using a paid email service when you can open a bunch of Gmail addresses and use them for anything. Additionally, Gmail has a very good spam filter so you won't be getting a lot of spam. The only problem is to remember which email you use for gambling, which one is for social networks and so on.
If there are people who pay to get an email with more privacy and that offers much more cloud storage , for example Proton is one of the most powerful email servers there is and they offer monthly and annual plans for emails, they have many Advantages, currently people are Looking for paid emails to have more storage, 1TB or more than 1TB, each one of us has needs based on that.