I had the exact same problem because I had a strong addiction to smartphone apps.

I looked into the Light Phone and The Mudita Kompakt, but I ended up buying a refurbished Pixel 8 and putting Graphene OS on it, then I installed only essential apps I need. I keep my old iPhone 12 in a drawer at home and use it for anytime I Need any apps that don't work on a custom ROM, which includes my bank app (plus, imo, it's safer not carry around a phone that has my baking data on it in case it gets lost or stolen).

The light phones are a really cool concept but the Light Phone 3 is quite expensive (more expensive than a new Pixel 10) and the Mudita Kompakt seems to have a huge amount of grievances from users on their forum, so that put me off.