So, because I can literally talk forever about this topic, now that I'm on a keyboard instead of a phone...
Here's the thing.
You and I, because we are complete nerds, can name some absolute legends at guitar that other complete nerds can also name. Guys like Jason Becker, for example. Now the point is not to say whether or not these guys are better than Ed, but to point out their relative obscurity. (And, you know, not just guitar; is Rick Wakeman a household name? You and I know who he is... but outside of old glam/prog rock nerds, who else has heard of him?)
It was Dave who:
Made them get out of t-shirts and jeans
Drove them to the gigs
Got them to write shorter, peppier songs instead of 17-minute long odes to Black Sabbath
It's really hard to overstate Dave's 1940s dance hall tunes influence on VH's sound and how much that MADE their sound
Put on the show every night
Worked every bit as hard as the rest of them because he was 100% all in
After Gene Simmons' band rejected them, gave everyone the pep talk to pick up their spirits and let them know that they were not. Fucking. Giving up.
And it's not just those concrete things. Ed and Al's dad himself told them: "People don't go to hear the band; they go to see the band." They went to see the hollowed-out bomb effects mount and the flaming drumsticks and the finger tapping and the cute young men jammin' but above all they went to see Dave jumping and wearing assless chaps.
Think about this, for a second.
Right now, wherever you are, there's a symphony nearby. In that symphony is a principal oboist. This person slaved at their craft for decades before getting that role, surpassing countless other hopefuls, mastering an incredibly demanding instrument. They have more skill and musicianship in one hand than almost every so-called "great" guitarist we've ever heard of had in their whole body, and they're playing a much more difficult instrument on pieces of music that are orders of magnitude more complex and deep than anything any dumb pop/rock/blues band ever shat out, and they are absolutely crushing this amazing instrument 2 nights and a matinee every week...
...in front of an audience of sleeping pensioners.
It's easy to see Ed the legend and think, Yeah of course someone that good was gonna be that famous without recognizing that there are people out there who surpass him on a daily basis, thousands of them, that you never hear about because they didn't have a marketing department, a bunch of roadies, a business manager, and above all a Dave who added just the right mojo to the music and to the show to actually make them famous.
And if you want proof of that, all you have to do is look at Ed and Alex's Dad. Why, if they hadn't invited him to play on Diver Down, where would you find a recording of him? Would you have heard of him without them?