I never got enough of this type myself, they were just random gigs between other types of project work.
IMHO, the IT industry as a whole has internalised wastefulness and accepted poor performance because there's an expectation that "CPU upgrades will fix it". Over five decades that was true, it's just that few organisations have adapted to the new reality of only ~20% uplifts in single-thread performance over the last decade or so.
In principle, there ought to be many more optimisation projects, but unfortunately they're still rare.