The usual use case for paying for something you could self-host, is that you don't have to self-host and therefore manage it. Someone else deals with installati

The usual use case for paying for something you could self-host, is that you don't have to self-host and therefore manage it. Someone else deals with installation, updates, and ongoing availability. For something like this there is perhaps extra factors like someone else worrying about abuse by malicious users and the resulting risk of being black-listed by spam filters.