The commercial alternatives hope to make money with every additional user. They use AB testing and statistics to streamline the on-boarding and to increase engagement. The result may not be in the user’s interest (doom-scrolling, ragebait, …) but it works.
For a fediverse instance, any additional user is a cost, not the promise of money. Financially, you wouldn’t want that. Those who fund instances are giving a gift to the world for their own reasons. You can accept the gift or not. Those who keep instances running with donations will usually want to sustain the community of which they are part. They probably don’t want it to change very much.
So, I don’t think matters will change. Partly because the psychological engineering is antithetical to the fediverse ethos (as I see it, in my humble opinion). But mostly because the outcome we see is an inherent result of the incentive structure.