[hereonout2]

Yes, it is incredibly easy if those files have no external dependencies - say a go binary for example.

The format of the .deb package itself is also pretty simple and straightforward.

But historically and probably now even almost all packages were nothing like this.

When you need to target particular shared libs as dependencies and link against them, confirming that via build isolation, etc - which is what the vast majority of packages have to do - then all the other complex tools become a necessity.