One thing I hate about the Linux desktop is the sheer lack of interest for supporting new hardware until it's too late.
Before you jump at me: I know it's not really anybody's fault. The contributors didn't switch to new hardware yet, and someone has to do the work.
But that does not excuse the passive aggressiveness. GNOME's stance on fractional scaling was, for years, "never happening - fractional pixels don't exist, so we do integer scaling only". A few years later, hidpi displays are becoming the standard and all premium laptops ship with them. Very few of them work fine at 200% scaling. One thing the Framework Laptop 13 reviews mention when testing it on Linux is that there is no optimal screen scaling available, just too small or too big - and that you can enable experimental support for fractional scaling, but it's a buggy mess and it's an option not exposed to the user for very good reason. Only now that it's too late and Linux is already buggy and annoying to use on modern laptops because of this we are beginning to see some interest in actually resolving the problem, including GNOME rushing to work on implementing support for it in GTK and Mutter, after years of bikeshedding. Somehow, things that are impossible and never happening suddenly become possible and happening when the writing that had been on the wall became true, and the hardware that a minority of users had been calling attention to for years is now common place and oups! That gives the Linux desktop some very bad exposure and first impressions.
Touch screens were another problem area. Initially the common stance was that nobody really uses these, convertible laptops suck anyway, etc. fast forward to now, more and more premium laptops offer touch screens, and stuff like 360 degrees hinges and convertibles that are actually decent are starting to surface. And, of course, everyone on Linux desktop wakes up and starts admitting that touch screen support is actually in a problematic state when it's already too late, and (prospective) owners of these devices have to pick between a very buggy experience that feels like Alpha state on Linux, and just using Windows.
It goes on. HDR support? Color correction support? FreeSync support being spotty and completely missing in GNOME Wayland?
I'm a heavy Linux user. I will nuke my dual boot when my next laptop ships so I'm going all-in after all these years. But I also own a 4k FreeSync monitor, a MX Master 3 mouse ane my next laptop (Framework Laptop 16") will require fractional scaling and VRR support to use comfortably. Having tried all these things side by side on my dual boot, I am somewhat jealous of how well Windows seems to handle these things compared to Linux. All this "nice stuff" has either taken a lot of time since my purchase to work nicely, or still doesn't work nicely at all. Ignoring contribution / manpower issues, this constant critical attitude towards new hardware and the unwillingness to try and properly support it is actively keeping us in the "Eternal 90% there" stage. We will not get out of it, because customer tech will keep evolving, and we will keep accepting new trends only when it's too late, and we're 7 years behind Microsoft in implementing support. It's not a secret that where Windows still obliterates Linux is niche use cases like HDR and colour accurate work, and support for new customer hardware, that usually lags 5-7 years behind on Linux.
You forgot cache distance. That would also critically hinder performance