But, if I wanted to buy the latest Adobe Creative Suite and run it in Linux, I have no real recourse.
So I guess in that sense, my statement could be made more precisely as: Obligate users of such commercial software suites as Adobe Creative Suite are captive users of either Windows or macOS.
But they don't, for the same reason you stay on Linux. The fact that you can run bash on Windows is not such a huge difference if for other reasons you don't.
They don't want an inferior experience, even if they could tolerate it if strictly necessary.
Perhaps—and I've certainly met professionals that claim to use those tools. However, I've met others who claim (rightly or wrongly) that Gimp and Audacity are not perfect substitutes for other commercial packages.
If you wanted to move to macOS/Windows you couldn't, because you wouldn't bear their inferiority when it comes to hacker things, so aren't you also captive?