EA has a PC storefront as well, though, so technically that is not a difference between the two, but I'm not gonna be disingenuous and pretend the two storefronts are comparable or as much of a priority. And published releases absolutely count, otherwise you'd have to tally each individual EA studio. Valve has published third party games, too. And, in fairness, EA has published Valve games in the past as well.
Either way, by any reasonable metric you choose Valve is at best as deeply invested in MTX and games as a service as EA. Unless you count "how many total games with MTX each has published", because when you make no games you make no MTX, I suppose.