That is not “basically it.” The documentation on the criteria is 44 pages. It’s not like programs just say I want it and it’s granted. Agree with it or not, it’s an arduous, robust process.
ME is the most popular engineering program. You can use it as a reasonable proxy for the total number of schools with ABET accredited programs in the US. It’s not exact, because a handful of schools offer only General Engineering. Most schools won’t offer the more esoteric majors like MatE, Nuclear or even ChemE if they don’t have ME. There are 344 ABET accredited ME programs in the US.