This person takes advantage of people who are unaware that they could just get it for free as well.

However, if this person is putting in an effort to sell this item (like advertisement or creating a platform to distribute this item more easily) then I don’t see anything wrong in charging money for that.

With software there would be infinite copies of that free item for everyone to get. So the dick move is to sell it to people who are unaware that they could get it for free.

Feeling like 1 or 2 right now

I have several mails for different projects. Also private + university mail. Then I have my Google mail that I exclusively use for everything related to android/app store.

Checking all those mail accounts at once, managing folders/filters and signatures is all way easier with a desktop mail client.

Some years ago I was like you. I only needed to read mail and I have to admit that a desktop client is not really necessary in that case.