

They are correct. It only means more work for future devices, makes the initial port to a device slower. But then, once things have been figured out. It becomes just as fast and reliable as it was (unless what I said earlier: Google setting things in a very different way in a major update (for example, moving to Fushia, which has been abandoned)
RMS warned of this a bit over 20 years ago. This is why you should get Free and Open source software and not Open Source Software. Preferably with a GPL licence which allows you to download, run, read the code, modify it and share it. Open source can mean you only have the right to read the code and signal to the dev code you’ve saw that could have been better or errors you saw.