There are enough people that don’t have the technical knowledge to host their own instance which happily pay Bitwarden to do so. If I host my own software and pay for the servers myself I’m not gonna pay a monthly fee just to be able to use the software. Maybe a one time payment, but definitely no subscription.
lol may I ask what you have to do to get that amount of spam? I at most get one spam mail per month to my server and I have some addresses listed as contact information on my public websites.