If you need compute with a bit more horsepower, the myriad of NUCs or thin PCs exist. If you need both in a single board, then the myriad of other SBCs that aren't Raspberry Pi's...
The main reason it was/is the popular behemoth is not because of it's tinkerability, but because it got mainstream appeal and RaspianOS is polished enough for the average windows user to go "wow, neat."
THere is no "knock off pi", there are many many popular SBCs with the same performance at cheaper cost (O-Pi, arduino), not to mention the mini PC space (NUCS, ie intel asus.)
Things get more expensive with specific ADC needs/etc
OF course, that shouldn't matter for most tinkerer jobs like a CarPi. But anecdotally, I tried using my old iphone 13 (idk why I tried this) and then a couple old galaxies for my car project taking data from bluetooth dongle and relaying to a custom gui I made. Of course also dealing with power cycles and screen, data trasnfer etc.
Very, very quickly it became easier to justify buying a SBC for the same project
I run a headless laptop as a server and it works great, and just sips power. It didn't have Ethernet built-in, so I just replaced the WiFi card with one and it worked just fine (and also let me panel mount the connector for a DIY 1U enclosure).
While I did not get it myself, I recently saw a business laptop I was hawking with 8GB of RAM and a relatively modern CPU sell for less than $50 on eBay. All that was wrong with it was a bad back panel; just some broken plastic which I wouldn't have been using regardless.
I could see myself running a whole rack of headless laptops in the future. It's more likely than me buying a single new Pi at these prices.
Forgot about that until you mentioned it.
I suggest you get a jetson nano instead if youre doing robotics or anything serious with an RPI.
If you just want a cheap computer, you're probably better off with a second hand laptop, probably cheaper too
They forgot to mention 99% of them are out of stock.