In 2019, Instagram only made around $11.98 per user annually.
Imagine if you could pay $12 a year and never see an ad, never be manipulated by an algorithm, never have to worry about any of that. All engineering would be focused on retaining you as a user, not as a market segment for advertisers. The incentive wouldn't be to addict you with an infinite scroll but to provide enough value for you to maintain the annual cost. Possibly even minimizing the attention it demands because the greatest profits is in justifying the subscription while encouraging the least amount of resource use.
Unfortunately, growth-hacking meant VC subsidized growth with free services and there was no way that subscriptions could compete.
The question is if anyone could ever sell low cost, user-centric subscription-based apps in a world where free (but not really) is taken for granted.