The text is sharper with a higher PPI even if the actual size of the text is the same. I have a 4k 24" screen, and text is much much sharper than on any FHD 24". Hell, it's noticeably sharper even than on my 14" FHD laptop. And sharper text helps with legibility, so I find I can actually use smaller font sizes more comfortably than the "regular" size on a lower-res screen.
You don't get more real estate, indeed, since that depends on zoom level. However, depending on your setup and habits, you may actually gain some. In my case, I use 4k at 100% zoom. I don't care for window decorations, interface icons and so on, so it's not an issue if they're small.
If you go up PPI by a percentage you can reduce font size by a similar amount. Too small to be legible? Literally move the screen closer. No need to magnify anything.
Have a 27" 4k monitor and a 42" 4k monitor? Move the 27" close enough that it takes up the same FOV as the 4k and you get the same experience.
This isn't like home theatre where you're constrained to the dimensions of a room (ie. wall or console location a TV sits on top of and seat viewing distance).
You don't want it too close, but it can be closer than that if you have normal eyesight. The line should be where your eyes have trouble focusing and add a small buffer. For me that's about a foot. So wherever you're comfortable looking at a smartphone (or really any object) is a good point of reference.
Otherwise this is a commonly propagated myth related to radiation from early TV sets.
My preferred setup in terms of screen real estate is 24" 2k (2560x1440) without scaling. In terms of PPI it's a bit low (122), but 244 PPI 24" screens are hard to get. 1.5x scaling is an option
I like 25x14 on a 27" and the fact that on a mac you have to buy BetterDisplay just to make it work about 80% as good as on Windows makes me... not at all surprised since I'm supposed to use an apple display with an apple computer, right?
Why not just get a 4K 27”? They can be had for around $220 USD nowadays. I paid that for mine.
I do dislike the fact that Apple removed decent support for lower resolution monitors, but I also don’t see why anyone would prefer them to higher res unless it’s a budget issue.
The core issue with 4k on Mac is that unlike Windows or Linux, Mac doesn't have usable 125%, 150% or 175% scaling modes. But at 1x font rendering on Macs sucks, and at 2x you basically have a fancy 1080p screen; it just doesn't fit as much as an unscaled 1440p screen.
This forces you into 5k screens, or tricks to make the OS do actually useful scaling.
4k is... too low res for desktop use on a mac. 25x14 upscaled to 5k only to be downscaled again to device native resolution by a $15 tool still gives me more usable screen real estate than a native 4k and the $15 makes it so text is actually legible...
By 25x14, do you mean 2560x1440? If so, are you saying that a $15 device will magically make a 2560x1440 monitor higher resolution than 3840x2160? If that's what you're saying, do you have a link that provides some detail on this because I don't believe it.
I'm also unable to believe someone would consider 27" 4K text illegible on a mac since that's what I use that every day and can read text comfortably. Edit: Unless you're using it unscaled, then yeah, text isn't that legible.
These are strange statements to make without any detail.
It isn't a device, it's a software tool. It doesn't make the monitor magically 2x the resolution; it can trick macos to render onto a 5k buffer and then downscale the output to the physical display so it looks not-broken.
I'm saying macOS is unusable on native resolutions - everything is either too small or too blurry, so a 4k display won't do me any good. 25x14 is the sweet spot for me, but I guess Apple decided I'm holding it wrong, because they want me to get a 5k display to get usable 25x14.
27” 5k (5120 x 2880) -> 218 PPI
32” 4k (3840 x 2160) -> 137.68 PPI
34” 5k (5120 x 2160) -> 163.44 PPI
39,7 5K (5120 x 2160) -> 139.97 PPI
Apple Pro Display XDR 32" 6k (6016 x 3384) -> 218 PPI