No point talking about L4, it is dead. 12 months support and that's it. Was not that great imo anyway. It is what you cannot achieve in L4 that is the issue - no range masking, no edge aware technology. Indeed selective editing is pathetic at best. Layers were not great either as they just slowed the thing down to a crawl (or a crash) and the app does not use the gpu. Lr also has its partner Ps and the two together just blow L4 out of the water. Luminar Ai is even worse, no layers, no blending and no ability to use the same filter twice on any one image, and the dam has all but been removed intentionally. Sorry but sky replacement is superior in Ps (as supported by the reviews I have read and my experience) if only because it gives you access to the layers thus enabling further adjustments to the mask and colours using Ps controls. Ps' masking is probably best of breed now so it would be useful to understand why you believe Ps foreground masking in sky replacement is inferior, especially as having access to the sky replacement mask allows one to correct the inevitable vagaries that will arise via artificial intelligence.
Good that you think Skylum has a good support team - many will disagree with that. So to conclude - to properly compare L4 to Adobe you need to compare it to the Lr/Ps combination and then the focus falls on all the things Adobe can do that Luminar cannot. But then they are not meant to be comparable are they? Luminar is designed for a very specific audience (as described by the Skylum CEO) and if you fall in that group, as you clearly do, you have every right to be happy with what you have. Most of us here are happy with what we have and there is, imo, no need for the paths to cross on this forum, except maybe when it is used as an Adobe plugin where it can be useful.