I work for a small company that produces a DAW and VST plugins. Supporting Linux is a huge amount of work compared to Windows and Mac.
The main issue is that 'Linux' is not a thing you can support. You have to pick the distros you want to support, and then once you've picked a distro, what versions you want to support.
And you need to use the C++ version that ships with that distro, so if you want to support old versions then the entire project is held back from using latest C++.
And distos aren't backwards compatible. ie when libcurl4 is released, they remove libcurl3. So you can't have one binary for Ubuntu 18.04 and 16.04.
So it means for every product, have a build for every distro / version combination you want to support.
So now the solution is AppImages where you bundle up your app with all dependencies like a container. Haven't investigated this yet, not sure it will work for plugins.