Does your current bike really need anything other than new cables, grips, tires, and paint?
Powdercoat paint jobs are surprisingly cheap and super durable.
You could have a “new” bike for $300 in your ideal perfect color that rides just as nice as a $2K brand new gravel/adventure bike.
There are companies making great tires for 26” wheels, and tire tech has come a long way from where it was 20 years ago.