But what if I want a faster horse?

To keep the line going up, platforms have to appeal to wider and wider swaths of a population, eventually lapping at the shores of a population that really doesn't care or want this service. But if you can hook them with some dopamine in a 5-second video, or a quest to rediscover some neat thing that they saw two page-loads ago but is now mysteriously gone from the very same list it appeared in, then you've clawed one additional user into your metrics and the VCs give you a treat.

These people don't care about the service and they're the worst users to cater to, but everyone caters to them because they're the only ones left. Hence, TikTokization.

What I don't get is at some point the marginal user increase for a change has got to be smaller than the number of customers you tick off and lose by changing things.

Is the idea that all services converge on the same N billion people target audience who wants something almost entirely unlike the initial product? I feel like "marginal" doesn't really capture this nuance if so.