It's pretty much "real". You can install every package in the repos via apt, and they should work. Caveats can apply with regards to stuff that needs extra adjustment for accelerated graphics or new kernel features.
It's not a font ... and it says LINMOB (for LINux on MOBile).
I drew it in GIMP ages ago (15 years maybe?); and did not have the time to come up with a new logo since. (I am not super happy with it myself - but it's not a priority, there's way more important stuff I don't have time for).
That said: Contributions welcome! (at https://framagit.org/linmob/linmob.frama.io)
This is great, even if at least one app in that collection is only available for x86_64, which makes it hard to actually run on a phone ;-) They also updated the Device Support section of metainfo guidelines: https://docs.flathub.org/docs/for-app-authors/metainfo-guidelines/#device-support . Looks like some apps on the KDE side still need proper metainfo to show up: https://invent.kde.org/teams/flathub/issues/-/issues/34
Modern Android? More like Modern GNOME - it's called adwaitapod and adwaita is the name of GNOME's style. :-)
No, it's just that when you use a mainline kernel, you're just not reusing all the Android (often user-space) drivers that make cameras work on Android and due to that stuff, starting from drivers for the SoC camera interface to the camera sensor have to be re-implemented. Whether you are on glibc (e.g., on Debian/Mobian) or musl/Alpine does not really matter.
Also, Camera APIs and the whole "desktop Linux" camera stack (think of things like debayering, white-balance) is nowhere near as developed as what Android has (and that, IUC, Ubuntu Touch can reuse on Halium by plumbing things together).
A Pixel 3a may be a good choice. It's older, but not huge—and it's very well-supported in Ubuntu Touch (and Droidian, both use Halium/libhybris to re-use the Android kernel drivers), and also in postmarketOS (mainline Linux 6.9.3 as of this message).
On postmarketOS, camera support is not fully there—the front camera is somewhat supported. Also, Wi-Fi is still a bit annoying, calls only work with headset on postmarketOS, so I would say: Use Ubuntu Touch or Droidian for now, and maybe move on to postmarketOS once it's a bit more solid.
It's somewhat SoC dependent, but the actual feature support depends on auxiliary chips. Of the well-supported phones, only the Shift6mq supports it in hardware - software support on mainline is not there yet though. The Fairphones 4 and 5 also have the feature. I have the 5, and display out works with postmarketOS, but audio support is still lacking, and USB peripherals (e.g., keyboard, mouse) are not supported.
Here's a list of more devices: https://www.uperfectmonitor.com/pages/list-of-smartphones-with-displayport-alt-mode
That said, there are other ways like DisplayLink and or GUD that may enable you to connect a display to a OnePlus 6 or PocoF1 anyway, some people have done it (and left video evidence on social media or YouTube. It definitely requires a customized kernel, and unfortunately, AFAIK the efforts have not been documented/shared (kernel config and necessary packages).
+1 for Gapless. My library is not nearly as large, but it's still plenty quick (no noticeable delay) with my 1 digit gigabytes library and IMHO the best native feeling media player on Phosh/GNOME Mobile.
It also does the Album -> Artist -> Song thing (which made me notice that I still have not fixed every error in metadata I managed to add to a part of my Library by blindly applying musicbraiz suggestions via Tagger, but that's just a me thing).