Looking at the Wikipedia page and the requirements for standing the way Epic is doing this looks at least for me much more in line with the given requirements.
Though I guess the Wikipedia page is a simplification of the reality.
The consumer welfare thing is just one factor of many to make a status-quo antitrust law case a real battle. There hasn't been antitrust victories for consumers in a very, very long time.
Epic had to get Apple to go do an anti-trust thing - in their opinion. So it's definitely required to bolster the claim.
Probably 100% of congress uses an iPhone. 100% of judges. Every lawyer. It's right in their face. 100% of them use Google, 0% use Bing. I don't think I know a single non-engineering professional, English as a first language adult who uses an Android device.
It's not some abstract situation the consumer welfare standard didn't anticipate; it's the now. Nobody is going to sympathize with arguments about choice because that hasn't been true for a while - nobody makes the choice, not among these people, for alternatives, so is there really a choice?