I agree that it isn't hard, but I'm glad we both agree it isn't trivial.
> I do wonder if many people actually care to work through that step
I don't think most people care to be honest. But I think what does matter is recount events. I often point to what happened in Arizona as a perfect example. It would be substantially easier to create a narrative that an election is rigged if the tallying is more complicated. Malicious people like to hide in complexity and will often oversimplify a complex topic. Because of this, I think one of the most important factors in creating a secure election is ensuring that the tallying system is simple. While malicious actors will always act maliciously, we can reduce their effectiveness through this simplicity.
I do wonder if many people actually care to work through that step; in all of the public discourse around the Alaska vote, it's simply presented as a table with the reallocations already summed. For example, https://fivethirtyeight.com/features/what-democrats-win-in-a....
The general algorithm of "reallocate the votes from the candidate that is being eliminated" is conceptually simple, even if it's annoying to tabulate. I do stand by my claim that it would be very easy to build a website that can visualize this process without getting bogged down in the tabulation. See every site that's giving analysis on the Alaska results for examples.
I want to see actual UX studies on this; for example has anyone polled in Alaska to see whether people understand the result?