A tax would be fairer than the actual system is. You have to pay a fixed amount regardless of your income. (At least in Germany and the UK)
I'd probably argue 'fair' would be per usage, or per television. The latter would even be easier to implement - just slap a duty on sales as with alcohol and tobacco.
(Actually, that would be great, the defining characteristic would presumably be the presence of a tuner (or network in today's age?), so it would create a market for television-like panels without tuners or consequently without being 'smart', I'd hope.)
It would obviously fairer if they made a paywall, but also defeat the purpose (they don't fulfill anyway).