I think paying $9/month in order to use it is a big barrier to entry. Many bitcoiners are hardcore savers and won't accept the $100 /year burden. It's also weird to have a third-party hosted node to get 'freedom'. I see two ways in which it could succeed:

1 - You get more for your money. $9 is cheap considering it's a bitcoin and lightning node that can do much more. Support BTCpay for the user for example.

2 - Have a cheaper subscription for those that already run their umbrel/start9 node.