Lol I'm also addicted to YT (not proud of it, but the amount of well-produced, solid educational content makes it a hard habit to kick).
I think TT's algorithm is the strongest selling point. Vine had even shorter content and even faster dopamine hits but ultimately died (I can't recall if Music.ly died or was absorbed before it met a natural fate). I can't speak towards monetization but I hazard that TT creators still make most of their money from sponsorships (like twitch and YT) based on that one Hype House thing. That said, the algorithm might be a bit overstated in its strength. Put enough creators together on the same place all trying to be relatable, add in the fact that people are going through dozens if not hundreds of videos at a time, you're bound to yield several hits. In this sense, I think TT is successful not directly because of its format, but in that it's achieved a critical mass because of its format, and that critical mass allows it to easily perpetuate itself.
I think the parasocial relationships aren't "better", except that TT is "better" than Twitch and YT because it's harder to develop these parasocial relationships. Maybe your theory about phone cameras is correct, but I think what's absent is that sense of _address_. On YT, creators will often call their viewers under some aggregate nickname, or make direct references to their audience in a way that invites closeness. Combine this with frequent references to their fanbases as "communities" and I think that YT and Twitch have developed something of a cultural illusion that TT has not yet developed (again, mostly second-hand as I no longer frequent the platform). Again, this remains to be seen, but I lean towards seeing IG as the model here: where you can have similarly frequent posts, cellphone livestreams, and videos (and now shorts). However, since IG is usually not criticized as heavily for parasocial relationships as YT and Twitch, I really think that the difference maker is the systems of address and sense of community that, at the very least, has not fully developed on TT.