Of course money has to be involved.. try asking them whether device X will be supported or try reporting a bug. First you'll be verbally abused by "BadDaemon" (https://gitlab.com/BadDaemon), then you won't get the answer and your bug (and patch) will just sit in the tracker, because as this incredibly kind guy will explain to you, they're volunteers, they'll fix the bug when they want to, or they will never fix the bug. They might support the device in the future, or they might not and you're not supposed to ask about that unless you want to interact with BadDaemon - this interaction is the only thing guaranteed there.
Of course there are awesome people there, like npjohnson or mikeNG, but a pack of volunteers just can't compete with big tech giants..
I also, more directly, mean that they do generally have separate versions of core apps.
Anyway I'm not sure that one of the oldest and most longstanding third-party ROMs anywhere in the Android scene would fail to meet the threshold for "serious."