Why don't cars have diagnostic software loaded onto their infotainment centers?

Modern cars have MASSIVE digital displays, loads of computers systems monitoring every subsystem and internal diagnostics running to the OBDII ports.

Why the hell can't we get diagnostic feeds on our console or infotainment center?

I'm not aware of any car manufacturers selling their own diagnostic ASICs, so it's not an extra margin to squeeze afaik...

What gives? Any insight into this beyond the usual muh corporate profits conjecture?