This is because people don’t want to pay the cost of software carefully developed to take maximum advantage of modern hardware. In specific niches like audio production where this is desired then prices run into hundreds of dollars for a single plugin to cover the development costs.
It's always this way. Just like most people are happy with Ikea furniture, so most people are happy with the equivalent of "Ikea software". It's good enough. For folks who _are_ willing to pay, you can buy everything from low latency audio gear/software to dedicated Internet bandwidth to high reliability SBCs.
And even then, quite a lot of that audio production software is very, very inefficient, primarily due to poor GUI development. There are a few popular choices of software that are very well-known for being CPU hogs, even relative to more complex software.
Particularly the business often doesn't want to take on the goal of improved performance when good-enough will suffice. Which can often make sense when you factor in increase development costs, reduced flexibility/maintainability, and reduced ability to recruit for people with the skillset to work on such things.
Then again, performance is often a feature in itself. In some cases it can open whole new areas of potential business. Often times it isn't even particularly hard to achieve, it just requires decent engineering practices.
Unfortunately good engineering practices can be hard to find/hire for, especially among a development community/culture that hasn't had to bother caring about performance for a long time.
