I think apps are better than dating agencies, and social gatherings are better than dating apps.

There isn't much value in a dating agency that an app deosn't already provide. Agencies can only match you with what they have in their pool, if their pool sucks so will your choices. So why limit yourself to their pool when dating apps gives you a much wider access and control?

Social gatherings are the best because everyone is there with a similar interest, so breaking the ice is really easy. Even if there are no targets in the immediate circle, being friendly with them opens you up to their circles, and you'll be personally vetted as a friend which lowers resistance.

This also applies to FWBs, there are communities for that sort of thing

110%.

Action that leads to failure is still better than inaction.