This should be obvious to any person who tutors people online. If you check out sites like https://schoolsolver.com or https://chegg.com they have become havens for programming questions. One could make the argument that it's partly the teachers fault for reusing old programming assignments. On the other hand, especially on something like school solver, there are plenty of programmers, living in 3rd world countries,…
They were havens for traditional engineering questions when I was in college too (Dynamics, Statics, Fluids, etc). Every homework question we had seemed to be available online somewhere and it let to kids simply copying answers instead of simply learning the same material they were copying. It got so bad the whole MechEng dept at my school got rid of homework in favor of problem sets that were solved in a given class…
It made homework not a test of how clever you were or how resourceful you were ... "collaborating" with your peers. It made it about solving problems with instant feedback. Waiting two weeks between doing a problem is a lot less helpful.