What is a computer science conference, really?
Most computer science conferences expect that, except in extraordinary circumstances, at least one author will present the paper in person. The paper is also, in most cases, published in the proceedings, possibly on paper and distributed to some set of people, such as a special interest group. 

The reason for this is that we highly value collaboration and face to face conferences give us a chance to sit and talk as well as interact with authors. 

If you publish in a lot of conferences you need to plan for the travel. Grant funding is one source, as is university funding. I think that personally funding your travel is not especially common, but possible. 

Note, also that many conferences attendees work in industry, not academia, where they do research of various kinds. It is common to see folks from IBM Research, or Microsoft Research, for example at many ACM conferences. They are funded by their companies. 

One option for a prolific publisher (we should all be so lucky) is to do a lot of collaborative work so that if you can't attend, say, SIGPLAN POPL 2021, then one of your coauthors will be able to. 

But no, it isn't just another way of saying "journal". 

I should also note that quite a few people attend such conferences even when they have no part in the program. They are just there for the collaborative opportunities and for informal meetings.