The standard argument is a straw man argument. Tired light is not photons getting scattered, and is not photons bumping into stray electrons.

Tired light is because there is a cost to traveling through spacetime. The photon is warping the shape of all the universe mass around it. The photon is doing work.

The intensity of scattering is proportional to loss of energy. It is impossible to detect such low scattering level in our visible Universe because it is full of gasses and dust, which created many many orders of magnitude stronger scattering, which is still hard to notice except for very bright objects near to dense clouds of dust. It's not possible to confirm or disapprove this argument yet.

Moreover, if we are talking about friction and medium (the Ether), then it was predicted long time ago[1], that discussion will be resolved in favor of Ether when Higgs field will be discovered, because Higgs field must be present everywhere, like Ether, and because medium is required for transverse waves to propagate. Discovery of Higgs boson and Higgs field was announced in 2012, so discussion is resolved, but we still call the medium as (physical, quantum) vacuum, like we still call atom as atom («unbreakable») after breaking it, or we use «-» for presence of electrons instead of absence of electrons.

(non-native speaker)

[1]: https://physicstoday.scitation.org/doi/10.1063/1.882562