I think journals should have a more uniform mechanism than asking reviewers to check a box or comment for ensuring completeness and usability of the data and code. But they should absolutely be provided in review for reviewers who do want to see for themselves how things were done.

I do appreciate your context here that review times in PoliSci/Econ are already too long, but I'd say ppl looking at code isn't the cause of that and as folks noted above having the code to refer to can actually speed things up.