> the strong force does a similar thing

No, in the heuristic approximation you are using here, the strong interaction does not weaken with distance; it strengthens with distance, so it takes more and more energy to try to pull two quarks apart, for example, as they get further apart (whereas the energy it takes to pull, say, an electron and a proton apart gets less and less as they get further apart).

So, for example, if you try to pull apart the quark and antiquark inside a pion, at a distance scale of roughly a femtometer, the energy required to pull the two quarks apart is large enough to create another quark-antiquark pair, and so you end up with two pions. You never get free quarks.

Similar remarks would apply to trying to pull a gluon out of, say, a glueball; you just end up making more gluons and making the glueball larger; you never get free gluons.