I think the lack of HOF is a contributing factor to the reduced number of hours I have played Civ6. I am enjoying some of the new features in R&F at the moment, but after almost two years, I have less than 500 hours played according to Steam (more than 2K hours invested into Civ5...and Civ4 did not track my hours since it was not on Steam, although I think it is probably higher than Civ5).
The lack of depth in the scenarios is also a contributor. I miss Smoky Skies and New World scenarios from Civ5. None of the Civ6 scenarios have been very interesting to play more than once or twice.