I am not sure what to do about the burnout problem. The way he described it is very on point though. Since everyone working on the project is overloaded there is a great feeling of things only get done if you do them.
Most of my open source work was in the pre-GitHub days when we used mailing lists, not pull requests, to build community. I do think there was something better about that for the project itself as it encouraged a lot more discussion and community building. PR's and Issues become silos and are not great for general discussion. I think they also encourage drive-by contributions which honestly are intoxicating initially but once you see people are not coming back become defeating.
Pacing and self-regulation. It’s a marathon not a sprint. Set an hours-per-week budget. Beyond that things just don’t get done. That’s okay.
If the community needs faster pace, they can consider supplying hours or dollars to fund more developers to work full-time.
Also, and this can be the hard part, is sometimes you have to have someone who (even politely!) can be a bit of a dick when necessary. People scan be quite entitled and want to boss everyone around and tell them the project is run wrong - if you don’t actively run at least some of them off the devs will curl up and disappear.
Also having a defined procedure for “hiatus” helps quite a bit - make it easy for a dev to say “I’m off” and it can be indeterminate - this allows them to easily come back later. Encourage devs to use it liberally.
As an Eastern European I always found fascinating how many Westerners are struggling hard with this. To me and many of my peers (and apparently to Linus Torvalds and a good chunk of the entire Nordic culture, probably?) it's the easiest thing in the world to say something like:
"Listen up dickhead, I do this in my free time. If you don't like the direction of the project or the urgency with which your issues are [not] being addressed, you are free to not use it, and it also costs you nothing to not comment at all. I got better things to do than to reply to entitled cunts, now piss off."
It's very amusing what a huge drama many Westerners make out of just... being direct. Honest. Straight to the point.
"But he won't ever contribute and he might infect others with the opinion that the project leaderships is toxic!"
OK. That's a price I am willing to pay. My mental health > the second-hand opinion of people who were only 0.1% likely to contribute anyway. The math is very easy yet so many Westerners struggle so much with these [to me and many] mega obvious solutions, like "be a bit of a dick when necessary".
This is really very similar to the discussions I had with a lot of women long time ago. It goes like this: they tell me:
"I have to go tell X and Y about event A because otherwise Z will tell them lies and they'll think something wrong about me."
To which I reply with a cold expression: "Then you don't need X and Y in your life, if they can be so easily influenced by lies and won't even ask you about what truly happened."
Their expressions were priceless. The cognitive dissonance can hit us all VERY hard.
Back to the topic at hand, yes, I firmly believe all open-contribution projects need a Linus type of person. It's also a fact that many devs are introverted and can be chased away by entitled and insolent loud people. So somebody must put a shield in front of the devs.