As for the candy analogy, I think that's a bit cynical if all you're critiquing is the login system without looking at the actual application. Lots of quality applications provide login via Facebook: Spotify, Notion, Airbnb, etc. It has nothing to do with the actual apps itself, it's just the doorway.
And to further clarify: I also wasn't criticizing your platform as part of my comment, I was referring to the status quo platforms - citing specifically all major platforms.
I do greatly appreciate anyone genuinely attempting to solve the problem - it's a very serious problem; obesity, literally, is a big problem in North America and growing globally (no pun intended) - and in big part is the capture of our information systems (including MSM/legacy media and platforms that have reached popularity and are ad funded/driven) by industrial complexes; with a sprinkling of foreign interests and bad actors interfering.