My current all road bicycle is built around an affordable aluminiun frame with 650b wheels and carbon fork. The only thing I'd wish for is extra rubber clearance in the front fork, as the rear is all right.

Good quality steel is quite light as well, about 2.5 kg for the frame and the fork. Add to that beefy 650b or 700c wheels with 42..50 mm wide rubber and you've got a bike which one can confortably ride on most roads, paved or otherwise. The new gravel bike trend is quite in line with this. As long as it's not an UCI approved discipline and the manufacturers start making only race bikes again, one can probably find a decent endurance or adventure model with more relaxed geometry and actual utility. I like the current Breezer Bikes lineup a lot, especially the Doppler. They're made of regular 4130 chromoly, not Reynolds 725 or other heat treated steel types, but they're affordable, very durable and also carbon fork compatible. Joe Breeze is also very experienced designer and builder, being one of the original mountain bike pioneers. If you want a more nimble bike look for a Ritchey or the more premium QBS brands like Salsa or All City.

Dutch style bikes are okay in flat countries like the Netherlands and Denmark, but I'd get a lighter trekking bike regardless.