I would say it's more of a matter of the level of interference of the fief on trade. When 100% of the economy is controlled by the monopoly on violence I would say that is complete communism, and when 0% of the economy is controlled by the monopoly on violence that is complete capitalism. This is a kind of asymmetric definition of communism/capitalism because "complete capitalism" is a pretty unstable configuration.
Joint-stock companies are not a prerequisite in my opinion; You can have an capitalist economy of merchants that run everything as sole proprietorships. Socialists will try to define capitalism around ownership of the means of production but I am not sure this is a useful definition.
Modern industry is more capital-intensive than labor intensive historical industries. So the sort of pro-labor communist movements that design systems that ignore the value of capital have pretty much gone extinct in the current era.
The "communist" party of china has adopted a number of capitalistic practices since deng xiaoping. At the same time, the "capitalist" american economy looks awfully communist under my definition as a significant chunk of the economy flows through the government, the military-industrial complex and such.
The main difference is ownership of the means of production/companies by the workers or by a separate group that might not work at the company at all.
- https://newsletter.semianalysis.com/p/tpuv7-google-takes-a-s...
It's also plainly obvious from using it. The "Broadly deployed" qualifier is presumably referring to 4.5
It's probably just a question of cost/benefit analysis, it's very expensive to do, so the benefits need to be significant.