I've read something along this lines before, but cannot find a good source for it. Do you have one?
Most free clones are not as good in various ways, and good clones that are charged for probably get earn their creators a letter from a foundry's legal team that makes them decide that the cost (time and money) of defending their position (even though they should eventually win) is not worth it.
First reasonable one that came up in a quick search: https://www.crowdspring.com/blog/font-law-licensing/#:~:text...).