The clustered markers in leaflet are jarring (I like them, but when I show maps I make my wife she finds the transitions nauseating).<p>The default heatmaps for these maps are bad. Heatmaps should use filled contours so the gradations are more easily identified. (Continuous raster maps are blobby.) See the ascii glyph map in this post, <a href="https://andrewpwheeler.com/2015/06/12/favorite-maps-and-graphs-in-historical-criminology/" rel="nofollow">https://andrewpwheeler.com/2015/06/12/favorite-maps-and-grap...</a>. I think those should be static for various levels of zooms as well, and not recalibrated when zooming.<p>Another option (not shown here) is to just use polygons and aggregations, and when zoomed in can turn on that point layer (or just have it appear). Or can just make actual clusters (like DBSCAN).<p>I have a map I made on my website that shows these (with various interaction tooltips/hover), <a href="https://crimede-coder.com/graphs/DurhamHotspots" rel="nofollow">https://crimede-coder.com/graphs/DurhamHotspots</a> (hotspots of crime in Durham, NC). And an explanation of the cartographic decisions and when to use the different techniques, <a href="https://www.youtube.com/watch?v=mBm6sTR08BI" rel="nofollow">https://www.youtube.com/watch?v=mBm6sTR08BI</a>
I have an app that is heavily map-based. It's an iOS app that uses Apple Maps <i>(I know, I know, controversy, yadda, yadda; but there's a good reason -many of them, in fact- that I use Apple Maps)</i>.<p>I found that the built-in AM clustering truly sucks, so I wrote my own. It's not perfect, but delivers a much better experience than the native one.
There are excellent examples of the problem in Edward Tufte's "Envisioning Information". Have a look at <a href="http://blah.ksteinfe.com/181106/tufte_envisioning_information.html" rel="nofollow">http://blah.ksteinfe.com/181106/tufte_envisioning_informatio...</a> for a few snippets of it, then buy the book.
Clustering is only asked for by someone that has no interest in or understanding of the data.
It does save a purpose. For example in the OP's non-clustering example all of the Britain is covered in dots, I'm talking at the highest zoom level, while the Atlas Obscura version, the one that uses clustering, does a better job of providing data by mentioning how many points that general area contains.
In such cases I generally prefer displaying counts of points in defined areas, rather than using clustering (e.g., when zoomed out, show counts per country, and when zoomed in more show counts for states or equivalent sub-national areas).
If you have less than hundreds of thousands of points, you can probably get away with drawing individual dots on the map. Computer screens are high res.
Then, the dots should be less than 100% opacity, which helps convey density wherever they overlap. It's feasible in overpass turbo with its rather simplistic MapCSS, so it should be possible in proper web mapping libraries.
>You don’t have to cluster anymore. You can just be.<p>Try to get Google Maps or Apple Maps running on a phone with more than 200 Markers/Annotations, then come back to me with that. Their performance is fucking dreadful. Google Maps released a new renderer that just OOMs if you're rendering a Polyline with 5k segments. Decimate it or face consequences.<p>As far as I know, MapBox is about the only one that has tolerable performance. Anyone else doing heavy work and using the gmaps SDK is figuring out tricks: overlay rendering (drawing on a canvas above the map, which requires expensive RPC calls to get visible bounds / map projection which makes performance shit if you're not careful and always lags a frame behind), intense caching of marker descriptors, careful management of markers (dropping 200 Markers from scrolling the map + adding 200? Enjoy your main thread work that freezes the map), etc, etc.<p>First party map tools are absolute dog shit.