I've been happily using "GNU/Linux phones" since 2008, with only 2-3 years around 2017 of using an Android device as a backup, so there's no need to "hope"; you can just act.
Then Nokia N900 with Maemo 5, in 2017-2019 augmented by Samsung Galaxy S3 with LineageOS as a secondary device since N900 was getting unusable for the Web by then.
And finally since 2020 up to now, Librem 5 with PureOS, which removed the need to carry an Android device again.
Does the phone last an entire day on a single charge?
With a Librem 5, its 12ish hours on idle, 20 hours on suspend, and 4-5 hours light usage.
If so, I might be able invert my plan: use the Linux phone with phone/5G/useful software most of the time, and a cheap android phone in my bag that only comes out for things that need the monopoly apps and tethers to the useful one occasionally when necessary.
The Fairphone 4/5 supports 5G, but I don't know how stable they are on pmOS/Mobian