Yeah, the vt52 had a very primitive special purpose processor. The ADM-3A (which is even simpler) was in fact implemented with off-the-shelf ttl chips and sram (but only had escapes for cursor position, and clear whole screen).

Given the HDL languages and cheap FPGAs we have today it is possible to do more with just FSMs and the icluded RAM/ROM, compared to using individual ttl/cmos parts and designing a PCB. I mean you could do a VT100 compatible if you really wanted, but doing it with an 8 bit micro is way easier to write & debug (and extend!).