TikTok won because it has an algorithm that works,
People are crazy for views and likes, and don’t mind the silliest content, not chronologically ordered posts, which none of the services u mentioned have.
What car are u using that its suspension broke at 50k, our old family car of 15 years never had once broken, an believe me it was used a lot on Indian village roads.
Let's Encrypt was introduced so that money will never be a barrier/excuse for https. In these days it must be a default feature. Pocketing half for something generated for free is not a good signal for me. Yes other half is donated but, isn't that supposed to be optional? Let's Encrypt is supported by huge organizations. And on fly.io, The customer is already paying for compute.