By way of comparison to other 'free' number providers IMO Textnow is highly useful.
It works for verifications when my GV or VOIP.MS numbers are refused.
It is used as a destination for incoming GV calls & allows me to use an (unactivated) phone to accept calls when needed.
Their SIM for 'free cellular' is in another phone which tells me that SIM has an activation error & will only make (cellular only) calls via their app.
Tried contacting their support about it, but nobody answered so I gave up on that idea.
All told, I feel quite blessed to have their 4.99/year number keeping deal grandfathered & plan to keep that as long as possible.
I do the same. I got my TextNow # in 2018 to have a Canadian phone #. I use GV as my US phone #.
I do wish the TextNow app had the same capability as the GV app to have multiple #s active and working all at the same time, because if it did, I'd probably also have a US TextNow #.