The big 3 telecoms operate in the US only. SpaceX automatically can cover any country on earth that let's them in. Why does Reddit keep missing this point Also telecom companies aren't undervalued at all, they have literally no growth potential in the US. They can at best siphon customers in between themselves but that's about the max growth they can do.
The top-voted reply reframes Starlink Mobile as a global land grab no domestic carrier can match, against a bear case that assumes a saturated US market. If that view wins, the big three are defending a market with nowhere left to grow.