The popularity of other equally-good services should have no bearing on whether a service has a "moral obligation" to do something. There's nothing preventing all the conspiracy theorists from deciding en masse to move to Vimeo, or setting up their own video posting system on Gab or Parler.
* Vimeo, Daily Motion, Lbry or whatever else have even less shares than desktop Linuxes vs Windows. YouTube is the only game in town.