The effort required may be much larger than you think. Eliezer finds it very difficult to do that kind of work, for example. (Which is why his papers still read like long blog posts, and include very few citations. CEV even contains zero citations, despite re-treading ground that has been discussed by philosophers for centuries, as "The Singularity and Machine Ethics" shows.)

If this is the case, then a significant benefit to Eliezer of trying to get papers published would be that it would be excellent discipline for Eliezer, and would make him an even better scholar.

A benefit that would follow on is that it would establish by example that nobody is above showing their work, acknowledging their debts and being current on the relevant literature. Conceivably Eliezer is such a talented guy that it is of no benefit to him to do these things, but if everyone who thought they were that talented were excused from showing their work and keeping current then progress would slow significantly.

It also avoids reinventing the wheel. No matter how smart Eliezer is, it's always conceivable that someone else thought of something first and expressed it in rigorous detail with proper citations. A proper literature review avoids this waste of valuable research time.