I think Elon has the right idea, you gotta dip their toes in the water, then jack up the price later.
When Oprah is seen dining at a restaurant, the restaurant gets more value from the PR than Oprah gets from the meal. That does not lead to the conclusion that she should go open a restaurant.
I mean yes, but that value might be so low as to not be worth paying for. Not even for the monetary cost, but for the effort involved in setting up the payment (entering card details, etc) and then checking your bill is what you expect for the rest of time. That tiny amount of extra effort might make twitter not worth it alone for some people, even without the financial cost.
And even that yes it does offer value I'd qualify in that the value might ultimately on reflection be considered to be ultimately a loss on net. For example a heroin addict gets value out of heroin, but on balance the value they get (a fleeting pleasure) often isn't worth the damage done to their lives, but you could say "well it obviously offers value or they wouldn't be taking it". Note that I'm not claiming twitter is addictive or damaging like heroin, just trying to point out that "must have value because they do it" isn't really a solid argument a lot of the time
He’s probably right, although it doesn’t generalize to most celebrities who do have a vested interest in paying to promote themselves.