I think an underrated aspect of this is also that YC is ultimately a VC fund and so they're talking about companies that have the potential to be massive, multi-billion dollar companies.

Many typical tarpit ideas (to do apps, habit trackers, note taking etc.) can be great businesses for a couple of people building software together but not have venture-scale outcomes.

I do agree that as soon as you get network effects (recommendations, marketplaces etc.), SOOOO much is tarpit.