In some respects the 6502, was an early RISC processor. Even though technically speaking it was a CISC one.
It's neither. It's more of a minimal instruction set computer (I can find a video of Sophie Wilson saying so), much like the PIC, 8051, DEC PDP8, Data General Nova and other of the earliest microcomputers and minicomputers.
[That didn't really happen the same way with mainframes (aka "computers" from 1940 to 1965) because the early ones were build by or for "money is no object!" government organizations modelling atomic explosions or whatever. It was only in the early minicomputer and microcomputer eras that "any computer is better than no computer" was the rule. And some IBM machines such as the 1130 or the bottom end System/360 too I guess]
You're right, although the original Motorola 6800 (I think Chuck Peddle, was significantly involved), was where the 6502 came from. It was a sort of, "cut costs to the minimum, but try and maintain speed and functionality".
So, Chuck Peddle left Motorola, who had rejected, his dramatically lower selling priced '6502', so he (and others), left and created a new company. The rest is history.
There were some similar microprocessors, similar era, which might have, at least in some cost optimisation senses, beaten it, there. E.g. The Z80, having a half-sized 4 bit ALU, which, because of its relatively large number of clock cycles, could fit that in, time wise.
Also, Motorola, did the extreme cost reduced (yet 8 bit to the outside world), 1 bit internally (i.e. bit serial), MC6804P2, which Hitachi and maybe others, second sourced.
Amazingly, I think it had a built in self-test capability. Presumably, to cleverly reduce costs, by eliminating, reducing the time to do it, by speeding up the time to test the cpu, on the production line.
I've heard the testing can and is, the most expensive part of making the IC. Because it is time consuming (on a busy production line), needs expensive personnel and very expensive equipment. Potentially even, very expensive, custom test hardware/jigs.
tl;dr
Chuck Peddle, realised, that a rather cheap, 6502, would sell like hot cakes, and be designed into all sorts of new products. He was right!
But didn't seem to be in a position, to maintain that market dominance. If he/they had, I guess I'd be typing this in on a 6 GHz x6502, with floating point, and full 64 bit (6502) improved instruction set.