I think that's actually pretty clear. Keep pushing for free and open standards. Oppose lock-in and patent protection racket.
The commenter is looking for a list of specific, actionable steps they can take to make sure AV1 "wins". Unfortunately (as the author effectively acknowledges), there really aren't any.
My worry about seeing thinkpieces like this is that Mozilla hasn't been able to influence Apple through AOMedia — it's not accidental that Apple is still missing from the front page — and so is resorting to general-audience emotional appeals. I'd go so far as to say that "here's how the sky will fall" posts like this are harmful to their cause.
In more practical down to earth terms, what you or any other regular user can do is to ditch Apple products and avoid paying them any money. Vote with your wallet.
edit - judging by the downvotes this comment is accruing it would appear Hackernews believes my cynicism is unfounded, which is quite nice.
> Tigt: I have no idea what you want me or others to do, even after reading this 3 times.
> Judy DeMocker [Author]: That’s a valid point.
I'm sure it was fun to write a post that imagines how the use of anything-other-than-AV1 ultimately leads football fans to firebomb police stations in 70 cities. But I'd rather have read a thoughtful post on actually-legitimate reasons to care about this.