Lots of problems can be nicely parallelized, but the cost of doing so usually isn't worth it, simply because the entity writing the software isn't the entity ru

Lots of problems can be nicely parallelized, but the cost of doing so usually isn't worth it, simply because the entity writing the software isn't the entity running it, so the software vendor can just say "get a better PC, I don't care". There was a period when having high requirements was a badge of honor for video games. When a company needs to pay for the computational power, suddenly all the code becomes multithreaded.