I thought of the abrupt stop as a deviation in convenience / increase in time (out of your control) that doesn't happen on public transit.

Right, but public transit also doesn't (generally) go directly to your pickup spot or destination, and likewise has to make a significantly greater number of stops that don't have to do with your route. Similarly, they can be held up by passengers.

The point is, in general, public transit routes are farther from your ideal route and schedule. Taxis and regular Uber/Lyft go direct, while Lyft Lines are in between, requiring some compromise on route and schedule (waiting for a match).

True. If you decide to do a longer post about the transit continuum, I'd love to see it.

I've built a similar continuum for all of the taquerias in my neighborhood considering price and quality.