The idea is that dev packages dependencies in lib folder, so when people retrieve sources, they also retrieve all dependencies.

But you are right, that this is some extra work for dev, so this is question of trade offs: do you want to deal with all C++ build tooling mess, or you are Ok to do some manual steps.

Another alternative is to use some popular stable linux distro as build platform, then many libs will be packaged as part of that distro.