Maybe it would help to make it more explicit that Mastodon works more like email than Twitter in that respect, but to be fair joinmastodon.org and also the new user onboarding tutorial do try hard to make that very clear.
Maybe the network will just evolve to value interactions that aren't centered around brand pushing. Maybe it will let the rest of the social ecosystem take care of that and meanwhile mastodon will do it's own thing.
Or maybe a mastodon instance will seek to distinguish itself by providing this kind of verification and become the de-facto instance for verified brands. (There's already a mastodon that explicitly courts business brands.) Maybe we'll even discover that we just don't value such a thing that much, when it occurs on a network structured to make it easily separable from the rest of social activity.
All of which is not to say we should waive away the problem, only that it need not be a conversation-stopper when it comes to the question of whether mastodon has offers "enough" value in its current form.
I met a bunch of people on Mastodon whom I find interesting, and I have conversations with. There's no need for me to verify their identity because I'm enjoying the interactions I have with them.
This is really how internet was originally envisioned to work. You don't need to know anything about the person on the other end, the interaction itself is what's valuable.