I think mints are similar to relays. Using few big relays is fastest, and if we all do it there is very low probability of missing some posts.

Same with mints, if we use few big ones it's fastest and we have lower fees (as most transactions would be intra-mint).

However, if we look at the current distribution of users per relay it's pretty good (plot from nostr.band)

Why is that?

The advantage of using multiple relays is lower probability of censorship.

Similarly, the advantage of using multiple mints is lower probability of rugs. Also, with mints there is an anti-centralisation influence, because you don't want to use the biggest mints as there is more chance of big rugs from the gov or hacks.

So I would say there is decent evidence that the distribution of mints will be more flat than that of relays.