For me, I chose Microshift Advent to install on 406 wheeled folding bikes for the range available on 11-42T and 11-46T cassettes for local hills, the wide choice of shifters available, the longer lifespan of a 9 speed setup over something with a skinnier chain and more sprockets, and the total cost (both for the original installation, allowing me to avoid buying another chainset, and the ongoing lower costs of 9 speed setups - 11 speed cassettes cost 3 times as much as 9 speed cassettes here, about as much a rear derailleur).
As COVID disrupted supply chains heavily here, having a rugged and reliable setup became more important than previously, when I might have considered a 10 or 11 speed setup. Plus, those costs for items that need to be replaced regularly like chains and cassettes - ouch! I guess I’m old school anyway, grew up with 2x6 friction shifters on steel road bike and then moved to 3x8 full rigid MTBs in my teens. I haven’t upgraded enough in the past to feel like a 1x9 wide-range groupset is a downgrade!
As ever, your mileage will vary
