I have had a number of Samsung devices that I bought specifically to test out the DeX capabilities, and it's really hard to say whether I recommend it. I ended up going back to a real PC, and it was such a breath of fresh air.
My setup was: Anker A8383 USB-C hub, 1440p 120hz monitor, USB keyboard/mouse
-Apps close themselves even when the RAM isn't full, and the "RAM Plus" feature which gives you 8 GB of swap on a 12GB RAM phone doesn't necessarily fix it.
-Multiple apps can play audio at the same time if you install Sound Assistant and enable the requisite feature (multi-app sound). Similarly, you should get the Good Guardians and Good Lock apps from the Galaxy store (or apkmirror if in Canada) and tinker with the settings to taste. This is necessary to get 4K60 support or anything more than 1080p.
-I use Kiwi Browser, which supports all Chrome extensions and otherwise works like normal desktop Chrome. You'll want to go into the flags and enable the zoom thing (search for zoom) and then enable the zoom option under Accessbility in Kiwi settings, to fix websites that don't scale correctly. Tabs get unloaded/lazy loaded in background due to RAM issue.
-Doing anything moderately describable as "productive" or "intensive" (example: google maps website) creates more heat than the phone can handle over more than 10 minutes. Do not buy a Snapdragon 888, or other weak processor device (I am aware it is old but some people like used phones). Things like particles.js, hidden autoplays, etc that don't cause issues on desktop waste TDP on phones. The problem isn't necessarily that the phone overheats, it's that Samsung makes it so that not only does the battery stop charging if it gets over 36 C, it actually starts draining. For reference, your body temperature is around 36 C. On the S23 Ultra, with the Snapdragon 8 Gen 2, it's more or less usable now, with some battery drain from time to time. Weirdly, the battery drain issue is solved if you use a charger that supports USB PD PPS. The PPS part is VERY important. If you look at Samsung schematics, you will see that the PMIC does normal USB PD and there's a separate chip for PPS. Not all docks support PPS, in fact I'm not certain if ANY do. This is an area where more research is required. Of course, the fact that the PPS chip isn't affected might not be a thermal issue, but rather a "Samsung forgot to throttle charging on PPS", which would not be a good thing to talk about then because I don't want them to "fix" this.
-I cannot imagine development would be particularly easy on this device. I briefly looked into getting VSCode on there and whatnot but the Android Linux projects seem to have fallen quite some from their former glory. While web based stuff is likely fine, the aforementioned memory and CPU problems will make this difficult to use for anything too serious.
-All of the current common remote desktop solutions i.e. RustDesk (slow performance), Parsec (keyboard issues, no zoom), Reemo (mostly works, no keyboard shortcuts, lag, thermal problems), TeamViewer (3fps), Moonlight (mouse capture issue, thermal problems), RDP (low fps) etc have some kind of usability problem that makes them difficult to use for this application, in case you wanted to use the phone as a thin client.