I could fall in love with such a phone. One where I can easily run Python processes inside screen sessions, which gather GPS and other sensor data for rapid prototyping, stream that data over a WebSocket connection, then some Bluetooth stuff in Go. Computing stuff.
I own the 3GB Manjaro edition of the PinePhone (same hardware as this one, AFAIK) and, while in theory you can do everything that you describe with it, it is hardly something you could use as your only smartphone for the day. (I still love it, though, and love hacking away with it!!)
However, as of today, there's a much better way of achieving what you're describing in an Android phone: Termux (1)
With Termux you can use an amazing number of regular Linux/UNIX tools, interface them with phone specific functionality (like GPS or other sensors) and still enjoy having a modern smartphone in terms of apps available, performance and battery life.
(Shameless plug: you can watch Termux in action in this talk from last year (2). It's centered around Ruby, but Python works just fine, too)
This is important, but sadly a lot of people don't seem to notice/care what Google is doing to Android. The question in my mind is whether the quality of devices like the Pinephone can get high enough before the functionality of Android drops below a point where certain things simply become impossible.
It's a shame we're losing so much useful functionality there.
Security is a worthy goal but getting rid of useful features just because Google wants to handhold Android users so much seems to me like throwing out the baby with the bathwater.
Back in 2006 you could run Python on Maemo. Which, true, was neither a phone nor smartphone. However, a little bit later they released the Nokia N900 and the Nokia N9.