What I found helped when I moved to a large 4k screen is when I stopped trying to eke out every last bit of space and started using my desktop as an actual desktop analogue again. Whereas I used to full screen, and snap to half or quarters of the screen, now I have a few core apps open that take up roughly a quarter, usually a browser and email, and other apps I open up and move around to organize as I feel the particular task warrants (generally some terminals that are all fully visible). I often drag the current thing I'm working on to the bottom half of. The screen so it's slightly closer and easier to see directly, and leave reference items or stuff I'm planning on revisiting shortly up top.

I also was thinking I didn't particularly like the large desktop and screen at first, but now that I treat it as a combined wallboard and desk space, I can't imagine going back (and using the large but not quite 4k monitor at my desk at the office always felt like a step backwards).

I do set default scaling for Firefox and Thunderbird to be about 125% of normal though, as I don't like squinting at small text. I generally like how small all the other OS widgets are though, so I don't scale the whole desktop.