The local walmart has 3 55" TV options for under $300 that are 2160p displays, and even more 43" options that are under $200. This is not a premium feature in TVs anymore.
You can argue that it is a premium content feature and NetFlix would certainly agree. But today you can shoot 4k on a new mid-tier cellphone, or for even less money on an older used flagship phone, and edit 4k video on just about any used business laptop of the last 5-8 years. It feels weird to call this premium with how accessible creating 4k video is.
Personally, I'm more annoyed at their increase in ads recently than at this limitation. I don't know what the acceptable limit is, but 5-10 ads at the beginning is clearly way too many and much more of a problem. I really want reasonable competition. I don't consider Floatplane or Vimeo to be that competition.