Key things that Civ6 got right -- that really enhance my enjoyment, that keep me coming back -- are the districts and the governors. Governors let me give a temporary boost to a city, to buff the builder it will produce, increase the chop yield, buy a district, for only as long as I need it. Then I can reassign/reuse the governor somewhere else. Very dynamic. Districts allow me to specialize a city like I did in Civ4, taking advantage of specific strengths.
At a secondary level of enjoyment, I love the variety of leaders and variety of civs. I like the tracking of GP points for specific Great People, rather than the simple categories of Civ4 and Civ5. I like adding support units (balloon, drone) to increase the range of my siege units. Since I pursue the space/science victory a lot, from Civ2 through Civ6, having additional steps appeals to the builder in me. I also like map search and map tacks.
Most importantly, I embrace the Civ6 metanarrative of "MOAR CITIES!!" Similar to my favorite Civ3, I like that my empire is rewarded for growing onto new territory. Through expansion I can provide more resources/luxuries to my people, which increases amenities. This growth mindset is a stark contrast to my experience playing Civ5, where my people were LESS happy as my armies/navies were MORE victorious.
Yes, I have notes about things that Civ6 did not get right, but we have other threads for that.