If you control the server you can serve ads and collect user data. Those two things make up the majority of reddit's revenue. So you are not wrong, but it would

If you control the server you can serve ads and collect user data. Those two things make up the majority of reddit's revenue. So you are not wrong, but it would be like saying "why don't restaurants just let the chefs host meals in people's homes?" ... because then the restaurant doesn't need to exist anymore.