To me, the main advantage of bottle conditioning is that you can control the carbonation more easily than reworking all the adjustments to a kegerator. I like my saisons with a high carb level, but I don’t have individual pressure regulators on each line of my 4-tap kegerator. To get them to have higher carb and pour well I need to accept that I’ll have to either have all my other beers with a high carb (eventually) or do a lot of working with turning pressures on and off and maybe lengthening the beer lines.
The secondary benefit of bottle conditioning (that I think you already hinted at) is that the beer may last longer in the bottle if bottle conditioned originally because that priming fermentation will eat up any oxygen that may have gotten in when bottling. No matter how good I am at bottling off my kegerator, there’s going to be an introduction of oxygen into finished beer.
Now, what do I do? I keg them because it’s easier for me and I tend to be impatient when I think a beer is done. I’ll deal with the carbonation issues. I also know this not the custom of saisons (or a majority of QC beer, or the current trend of hazies…), but I love the look of a crystal clear beer when hoppiness-level allows. If I can pour a whole bottle of beer into a glass and not worry about stirring up some yeast or trub, I want that.
Last - The Brulosophy Podcast just had a show on just this topic… worth a listen
https://brulosophy.com/podcasts/thebrulosophypodcast/ Episode 176 Methods For Carbonating Saison