The same argument applied when going from laserdisc to DVD, then from DVD to Blu-ray. Plenty of people, on this forum, said the older formats were "good enough" at the time. It took quite a bit of time to get things "done correctly" for DVD and blu as well. Why dump a superior format which is...
The increased resolution is only part of the appeal of 4K. HDR/Dolby Vision plus expanded color gamut would make a big difference on some titles if done correctly. That is effective no matter the size of your screen. For me that is a much more compelling argument for 4K.