Your suggestion is closer to a grid computer but even then I don't think an unmodified 6502 would be a great choice because the memory model (or lack thereof) would really restrict performance.
[1] https://booksite.elsevier.com/9780124077263/downloads/advanc...
Intel did entertain a similar thought for a while, as far as I can understand: https://semiaccurate.com/2012/08/28/intel-details-knights-co...
The LAN controller used to make the Beowulf cluster would probably have more compute (and memory) than the 6502 itself.
The Intel cores in the linked article have a distinct L1 data and instruction caches inside them, and associated L2 caches, which makes a big difference in comparison to the 6502.
https://www.copetti.org/writings/consoles/dreamcast/#archite...