Re: 4K?
Hmmm ... you may be underthinking this...
Higher quality cameras will result in better images even when downrezzed, all else being equal
Conferencing video codecs are pretty clever these days
There are a lot of different working environments - I can still save anything up to an hour over a "walk across the office" by delegating that to our high-speed, low latency campus network.
Even at the home office, (4g wireless broadband 70/25 Mbps), the video and audio quality is still noticeably differentiated
Also at home, we have no aerial, no landline and no trouble streaming 4K in a semi-rural environment
Back in the days when we were all on-campus, team meetings could easily generate 20-30 mins of faff/overhead even with a meeting room on the same corridor as all our offices
Guest speakers are a breeze
Online support is a breeze
I have an HD webcam on top of my desktop monitor and a 4K cam on my laptop. The built in cam on the laptop is a POS and my regular meetees can tell the difference between all these setups both in audio and video quality.
You don't need a whole other setup to make high quality video lectures/presentations (you can switch the lights on and select the pro-grade mic for a little extra when needed). These can be uploaded to YouTube, Vimeo or our in-house video portal according to purpose.
The world is your oyster...
In non-work contexts, people are really quite up to speed with Teams and Zoom
Network reliability is somewhat better than transport reliability and miles cheaper (a month's connectivity is approximately 2 days on site)
YMMV but there are lots of wins to be had :-)