This obviously depends on where you are and where you’re going, but for example the region I come from (western Plalatina) has a full second road network built

This obviously depends on where you are and where you’re going, but for example the region I come from (western Plalatina) has a full second road network built by farmers for farm machines. It’s even denser than the “regular” road network. And it’s open to cyclists. You can go pretty much anywhere on paved roads and you’ll only occasionally meet a farmer. Other regions have discovered cycling tourists as income source. I’ve made the entire stretch from the Baltic Sea to Berlin by cargo bike with our 18 month toddler without major stretches on any public road. A large chunk is on the service roads for the oder river flood dam works. A similar path exists on long stretches of the Rhine river - my parents and I made the treck up the Rhine to the Bodensee when I was like 14 or so. And that was like 30 years ago, things have considerably improved since then. Sure, it does take some planning and consulting maps, but it’s not impossible. Especially since mapping applications have started to support bike-friendly routing. There’s also companies offering per-planned trecks where they transport your luggage and you just take the ride. And then there’s the Netherlands where they probably wouldn’t even be able to parse your statement. I sometimes have the feeling they get born on wheels.