Need to be clear about language at this point:
https://en.wikipedia.org/wiki/Actual_infinity
- The points on a number line is only a potential infinity not an actual infinity.
- As you look finer, you see more points so it tends to infinity but never actually reaches actual infinity. As in a limit. Never reaches infinity.
- Physically, it’s impossible for matter to exist with size 1/oo, so you would run out of resolution before you reached actually infinite points
- But an infinite set has already reached actual infinity which is impossible. You cannot construct an actually infinite set so by extension you cannot have an actually infinite number of points on a line segment.