It's a weird situation, but I think PlatformIO built up a dominant position by supporting all these platforms and accepting community contributions to do so, then tried extracting value from the manufacturers directly after the fact, blocking further community PRs that would add new board revisions or fix bugs. See related: [2]
[1] https://github.com/platformio/platform-espressif32/issues/12...
[2] https://github.com/platformio/platform-raspberrypi/pull/36