Correct. But when I looked into it a few years back fir OrangePi it was not as easy as downloading raspbian. All the images made for the pi would not work, you had to download a kernel from another place or something like that? Sorry I don't remember the details, but it was not as easy as a pi.
How much cheaper then 50 bucks can a tablet get? With the pi I can quickly in a hacky way connect rotary encoders with female-female dupon cables, use a python GPIO library made for raspberry pi.
https://media.discordapp.net/attachments/1461079634354639132...
I can also use it for Zynthian. And if I'm done with it, I can build a new printer :P
I think the part you're missing, is how expensive the Pi is now.
Buy one with a psu, and you're 100 to 150.