I'd argue that 68K is simpler to learn and use. You get a similar instruction set, but 32-bit registers, many of them. It's even got a relocatable stack so it can handle threading when you get to that point.
I agree, I feel like the 68k architecture was a dream for assembly programming. each register is large enough to store useful values, there are lots of them, there are instructions for multiply and divide. This allows you to focus on the essence of what you want to accomplish, and not have to get side-tracked into how to represent the X-coordinate of some object because it's just over 8 bits wide, or how to multiply to integers. Both of these seemingly trivial things already require thought on the 6502.
If 8 bit: 6809. If 32 bit: 68K. Those are miles ahead of the 6502. Otoh if you want to see a fun quirky chip the 6502 is definitely great, and I'd recommend you use a (virtual) BBC Micro to start you off with.
Sucked, compared to? If the 6502 sucked on every other metric but cost, while it would have gotten some use I don't think it would have been as heavily used as it was.
“The 6800 was initially sold at $360 in single-unit quantities, but had been lowered to $295. The 6502 was introduced at $25, and Motorola immediately reduced the 6800 to $125. It remained uncompetitive and sales prospects dimmed. The introduction of the Micralign to Motorola's lines allowed further reductions and by 1981 the price of the then-current 6800P was slightly less than the equivalent 6502, at least in single-unit quantities. By that point, however, the 6502 had sold tens of millions of units and the 6800 had been largely forgotten.”
Because none of the existing software would work. The idea of running a Rosetta-like feature on an 8-bit CPU isn't feasible. The Apple II eventually received an upgraded processor, the 65816, which was compatible with the 6502.
Though a problem, as you point out, it still happened. The 6800 based SWTPC was followed by 6809 machines what need to have all their software reassembled.
On the other side of the cpu wars, all those 8080 machines moving on the Z80s got to keep all their binary software, which happened again for IBM PCs and clones as those evolved.
LLVM includes an equivalent to binutils, with a macro assembler, linker, objdump with disassembler, library tools, handling formats like ELF and raw binary etc.
LLVM-MOS includes all of that. It is the same process as using LLVM to cross-assemble targeting an embedded ARM board. Same GNU assembler syntax just with 6502 opcodes. This incidentally makes LLVM-MOS one of the best available 6502 assembly development environments, if you like Unix-style cross-assemblers.
Simple architecture and really really joyful to use even for casual programmers born a decade, or two later :)