That is a good point (spiderfy is good if you want to show multiple icons and click on each one specifically).

If you do not like the cluster-marker, you could have an icon just list the total number at that location, and then on hover (or click for tooltip) show the table. And that may honestly be better than the spiderfy example for most applications now that I am thinking about it.

Maybe a better example, ESRI when you click a popup has a series of HTML, https://data-ral.opendata.arcgis.com/datasets/raleigh-police..., so if you click one of the grey circles it contains multiple points, you can basically go through different views (either all the elements or click through to a more detailed view of the individual point).