What platforms support 4:4:4 video? Youtube, Twitch, Vimeo, ... all don't.
We've all had enough experience with Zoom, Google Meet, Skype for Business, etc. in recent months to know that this is not something that works well out of the box. And that's before we get into issues like the fact that I'm using a 34" ultrawide monitor, and most streaming systems will have to downscale my desktop before encoding it, and the result won't look at all good for a viewer trying to watch on a 1080p laptop.
I find it simply amazing that all these "collaboration" tools aspire to little more than emulating the use-cases of broadcast television or a large lecture hall, and there a so few tools that try to enhance the experience in ways that are only possible when every participant has their own screen and computer.
A few tips for coding screencasting:
For coding screencasts you should make sure that chroma subsampling isn't enabled when you're doing the encode of the video otherwise it may look worse with highly contrasting areas.
Decrease the encoding frame rate if its primarily going to be just a screencast without a lot of motion on the screen. At the expense longer mpeg segments (and more latency) you may want to increase the group-of-picture size.
There shouldn't be a reason that the encoded screencast looks worse then how it appeared to you unless the encoder you are using is just mashing the quality down.