I have a chink phone. I recently replaced battery and the whole PCB where the USB-C port was located (because it got wonky)
costs? ~25 €
A friend of mine broke his iphone oled screen a while ago. The spare parts cost about 180€ (+ Programmer for ripping the eeprom of the old screen) and that thing was an overengineered nightmare to take apart and had lodged some moisture, as I found out when taking it apart, as the rubber seal apparently detoriated in one corner at some point. (My guess is some cleaning agent managing to work it's way in) My phone doesn't even have one, just a snapped on metal case, secured by two screws. It relies on the shape of the case+physics for being water resistant. (not waterproof, but neither is the iphone) Quite a good design actually, simple but I liked it. I bought it because it has a long history of being supported by LineageOS and being cheap. I don't really use it for much.
Same friend also bought an iPad and we played around with it trying to use it as a desktop in some way, do some game emulation, even configure it for game streaming from a PC. Eventually we gave up in frustration. It's insane how locked down that thing is. Apple intends it to be a media consumption device first and foremost and it is noticeable. There's a way around some of the limitations by buying a "developer's pass" you have to pay for I think it was annually but jeez. It was like pulling teeth. Apple truly thinks it is not your device, but you're only allowed to use it.
Ironically I think one of my favourite "laptop replacement" ideas has only ever actually been implemented by a low-end Android manufacturer.
You can do that with any phone/tablet where the USB-C port is also a DisplayPort and allows receiving power while being used as host. (otherwise your battery will be dead in five minutes - you can even skip the display port part, there's some specific IC in some docks that works with proprietary software and is basically a low latency video stream decoder hooked up to a HDMI or DP port) The USB-C spec has all this.. it's just rarely implemented completely. Android even has some tentative support for stacking windows last time I checked. The biggest problem probably would be getting good performance out of these devices because while they often have very impressive SoCs on paper, they're usually significantly thermally limited by the device they're in.
When some penny shaving bean counter looks for a way to look good in front of the execs, the USB-C implementation on any given device is usually the first thing that suffers as a result. USB can do a lot of fancy shit, you can even connect two PCs directly via USB 3 and have a very fast connection. Bet never heard of that one either. Because the ICs allowing the port to switch modes and be used that way cost a little more and are basically never found in desktop PCs and only sometimes in Laptops. That's why USB-C is always such a fucking mess, you never know which subset of features was actually implemented.
Also remember that USB-C is not only 5V but can negotiate for different voltages, that's why such a high wattage via an USB-C port is quite possible. If it's implemented properly on your particular device on every port though...