I'm not denying that some work has enobling aspects (e.g. social recognition (in various forms)), but much work doesn't. Speaking from years worth of bitter experience ...

Moreover there is probably quite a bit of rationalisation going on: since I can't avoid work I might as well pretend I like it, for that makes life more bearable. More importantly, there is a virtue-signalling aspect to finding work enobling: since human emotions are contagious and human behaviour involves a lot of mimesis (= copying others), my public display of taking pleasure in my own work increases the probability that others find their work enobling, which in turn increases the amount/quality of their work, and that leads a better / more productive society which in turn is in my own selfish interest.

Aside: Max Weber uses a somewhat similar (but more elaborate) argument when he seeks to explain the emergence of modern society out of the protestant spirit. The issue of whether we do good because doing good is intrinsically good or because we crave the social recognition of good works, has been discussed since antiquity, see for example Plato's Republic.

   What will replace it culturally 
   when we don't have any work?

Why not look at the facts? Society has always had some members who did not have to work, for example children, pensioners, the sick, the offspring of the very rich, wives of middle/upperclass husbands (until recently), women who divorce a rich husband (under current US alimony laws), the Saudi/Qatari/Bahreini/Kuwaity royal families. Etc. Most of them don't have a major problem spending their time. Typically they engage in a variety of play, fornication, sleep, sport, shopping, eating, hunting, socialising, playing music, drawing and the like. Moreover, even those who work have leisure time (e.g. weekends, evenings, holidays) and generally have no problem filling that time. There is no reason to believe that this will change when all work has been automated away.

I believe that the primary reason people give when stating why they enjoy their work is that, to them, "it doesn't feel like work".

If you are lucky enough to be paid to "do what you love" is it work or is it a hobby for which you are paid?

Hobbies, ie. work you you enjoy and are not forced to do.