Note: Linux distros still provide free downloads for Ardour, and Ardour's source code is free for anyone to build. Ardour's official binary builds are what is behind a paywall.
Also the "locking downloads behind a paywall" only applies to scores that users have uploaded to musical score social media sharing site musescore.com, but the desktop program MuseScore binaries are available for free on Win, Mac, Linux, BSDs via https://musescore.org/en/download. You can anyway post your scores anywhere for free. And there may be proprietary VSTs that you can pay to download via MuseHub, but MuseScore's baseline audio synthesis (as well as any free soundfonts you can freely download) are free.
Also the "locking downloads behind a paywall" only applies to scores that users have uploaded to musical score social media sharing site musescore.com, but the desktop program MuseScore binaries are available for free on Win, Mac, Linux, BSDs via https://musescore.org/en/download. You can anyway post your scores anywhere for free. And there may be proprietary VSTs that you can pay to download via MuseHub, but MuseScore's baseline audio synthesis (as well as any free soundfonts you can freely download) are free.