I suspect the primary value in 'regular' fixed moderation elections would simply be that the company would have to dedicate (more?) resources to it.
... haven't held elections since at least 2020:
Isn't a great metric. We get asked every so often if we need more moderators, and Super User dosen't need more for now. This would change if one of our more active moderators left but least for now, we can manage with 'losing' a moderator for a week or two. We might want to look at it at some point but - the lack of elections isn't really due to a lack of care, it's due to the lack of need.
Admittedly our statistics are a little skewed by spam handling (and low complexity flags), but we have ~5 minute flag handling time on Super User, We deal/respond to meta posts pretty promptly - essentially, we do alright right now.
Moderation seemingly helps manage issues like spam accounts, unhandled duplicate tags, long review turnaround times, and limits even trying to add to review queues (especially askubuntu), etc.
Many of these things don't scale linearly, nor do they 'really' rely on having more moderators to deal with.
Super User currently gets 1/3 or half the spam on the network. Anecdotally speaking, a single mod can deal with most of them over the day. We do have additional reporting methods and my 'tooling' for this is a little better but having mods available at the right time (that's to say geographic diversity) has helped us more than quantity of mods.
Catija covers most of the points I wanted to make in her answer. Practically this is a design/visibility issue + more per site meta usage would help.
long review turnaround times, and limits even trying to add to review queues
Isn't a moderator issue at all - it's a sign of either a community that grew too fast for its tools to catch up, or a community that's declined enough that the high rep users aren't spending time on the review queues. And a community without enough people involved in curation and metamoderation are going to have trouble finding moderator candidates.