What's the difference between legacy and actively supported?

Just wondering, as I’m looking into what device I should get to try this out (have an exynos phone currently so no use). On this page it shows actively supported devices, with “legacy” devices. Usually legacy sounds like something to avoid but in this case it looks like legacy has more feature complete devices. So just wondering if there’s any reason to go for actively supported over legacy? I also noticed some devices are on both lists. Is there like a new version of project renegade that is improved but still not fully implemented? The main issue I see is that almost no actively supported devices have audio working, which is a deal breaker.

Any insight would be greatly appreciated. Thanks!