> Given a simple problem A, when adding more options, at some point, choosing among the options requires more effort than solving the simple problem
Only if you require that every option must be assessed. You can always choose a random subset, or the first X entries, as use those as the solution space. Additional solutions provide for additional strategies in choosing a solution, but at any time you can ignore additional solutions and treat them as if they don't exist.
> And in practice, GP is right: with humans, too many options eventually only distract from the problem.
The whole point of government is to provide a structure such that decisions like this can be made be reducing the set of people that needs to reach consensus to a manageable about. Those people can choose to accept or ignore any solution presented, and call on whatever expertise they need to make that decision.
The whole idea of there being too many solutions only makes sense when you you apply it towards the general public and people whose job isn't to make such a decision or be domain experts. Since those people aren't the ones actually making the decision, providing too many solutions to the problem to them is a non-issue, and for the actual decision makers and domain experts they have on call, additional solutions are beneficial.
Whether you or I are getting overwhelmed with the possible solutions is irrelevant. We aren't ultimately the ones that will decide what action to take (at least directly), and we aren't the domain experts advising those that will decide the plans (or present the ultimately small set of options that are valid). At least I don't think so, unless you're a domain expert, but even then, your role would just be to provide advice (or if you're a politician in charge of making this decision, but that's even less likely).