Why did nobody use it before the Raptor?

I understand why Raptors use methalox, as it can be produced on Mars. But many of these new rockets are not destined to be refueled on Mars.

Another advantage is that it burns clean. That doesn't matter for expendables, but it's a big help if you want to reuse your rocket a bunch of times.

> Why did nobody use it before the Raptor?

It’s not the best choice for an high-budget high-performance expendable multi-stage rocket. Using kerolox/SRBs in the first stage and hydrolox in the second stage gives better overall performance.

Metholox is better for re-use, using the same engine in multiple stages lowers costs and complexity, and you can produce the fuel on Mars.

I think it should also have better thrust than hydrogen, so more suitable for first stages.