Tablets and a mini-PC in lieu of a laptop

I use Linux pretty heavily. One nice thing about Linux is that the UI is inherently client-server: you can run the apps on one machine and interact with them on another. This is kinda like the old days of having a mainframe or minicomputer and a bunch of terminals but these days we call them an app server and a bunch of thin clients. You can also use a Linux system stand-alone, such that the apps and the UI are all running on the same hardware. But you don't HAVE to do that. You can have a really lame computer networked with a power-house app server and accomplish quite a bit in a timely fashion, with the lame computer functioning as a thin client and the app server doing all the heavy lifting.

I went looking at laptops recently. For every single one of them I can find, the keyboard sucks. Bad. Since I do a metric s**t-ton of typing, that's a problem. Couple that with a touchpad which you can't help but inadvertently swipe while typing and ... why do people put up with these things? You can always disable the touchpad when doing a bunch of typing but you have to re-enable it when you need to use it; enabling and disabling it, repeatedly, gets old. You can always use an external keyboard and mouse instead of the built-in hardware but ... if you're going to to through the trouble of hauling an external keyboard and mouse ... why are you paying through the nose for a laptop? It's expensive and it eats up desk / lap space.

I want to be able to use one (or more) tablet(s) as display(s). I have one and I'm going to carry it anyway. Those are pretty lame on processing power, and you can't really run desktop apps on those, so I want to interface that to a mini PC (thinking Raspberry Pi sized). I want to be able to use an external keyboard / mouse to drive the mini PC. The mini PC should also be able to connect to Ethernet or WiFi, as well has having a DisplayPort socket so that, if I'm going to some office and they provide external screens, I can use those.

The mini PC should be able to use a USB power supply or run from a USB battery pack. It should have at least an i5-class CPU, SSD storage, ample RAM and the ability to run a full stack development suite (Eclipse, MySQL, Apache, Libre Office, Chrome, etc.). Everything you would normally be able to run on a laptop should be able to run on this thing. And before you think this is unrealistic, the RasPi 5 has better benchmarks than the last laptop (with an i5) that my employer supplied. There are a couple boards out there which make a RasPi 5 look slow. ExplainingComputers.com even did a video about editing video on one of these things. They aren't "high-end workstation" class but they're not toys either.

Plug the mini PC into power. Connect it to Ethernet, WiFi or a phone (tethering) for Internet access. Connect the tablet(s) to the mini PC via USB; this provides data connectivity and power to keep the tablet charged. Run an app on the tablet such that it functions as the graphical display part of a thin client. Use whatever keyboard and mouse you want (BT, USB, etc.). It won't be as compact as a laptop but it won't cost as much either and, as time goes by, you can always get a larger tablet, a faster mini PC, a larger battery, a different keyboard / mouse. You can upgrade incrementally. You can't do that with a laptop. You can always use the tablet as a stand-alone device when you don't need the mini PC. The keyboard and mouse can be used with any computer, such that you use the same keyboard / mouse whether you're at home, on the road or in the office. Maybe connect multiple tablets up in lieu of multiple screens; thin clients have been able to do that for decades (go looking for Sun Ray thin clients for more info).

Everything I'm describing should be do-able with modern tech. I just don't know of anyone actually doing all of this.