Promote purchase?
How? You never gave google the money

Use of google device?
If you promote the logo while using? Maybe.
Use a case or cover it with something like a vinyl skin. All phones look almost the same now anyway.

Thriving second hand market.
Yes. I can agree buuuut just buy the model from 2 years ago (assuming a new model every year) for >50% off, swap the battery and your somewhat good with an acceptable phone.
They don't hold the value as an iphone so this isnt too far off.
But if you buy the previous model right after the launch of a new one for 20-25% off then yes, you are fueling the used-market prices.

Example:
The canon 90d was selling with a kit lense for about 900-1000€ in a very good condition.
I filtered sales on ebay and made myself clear to buy it for 100€ or less.
A few weeks later I scored the sale for 800€ with 2 batteries and the whole packaging. Body was also only lightly used and a bit of dust specks inside the lense.
You can make good deals if you want to. Mindlessly consuming will result in what you describe.

Personally I would swap the battery in my phone if the storage wasnt a bit small for me.
And if I get myself a 256gb model next time I might have enough for the next time my battery has only 80% leftover capacity and I will attempt the swap instead.
I will also avoid getting a Samsung (bloatware), OnePlus (exited EU market. Had bad experiences with their OS flavor), Sony (tempting but way too expensive) and Apple (Is on my blacklist for the walled garden).
Googles phone are still affordable enough and has acceptable photography quality on par with Samsung, Sony and Apple.

So what else can you recommend me?
I need solid battery life (doing daily gps tracking with gpslogger and dawarich) Able to automate tasks (I found Tasker and probably can never life without it anymore :p)
Able to shoot photos (acceptable for a photo book if my DSLR isnt handy)
256GB
Budget is around 1000€ or less. Prefer to keep it around 800€ or less. Doesnt need to be cutting edge.
No need for headphone jack. Am fine with my BT headsets.