My map is super fast and nice until I click my "houses for sale" layer, which adds less than 3,000 markers onto the map on its own L.layerGroup(). It really makes it difficult to zoom in/out and pan around. It's virtually unusable in this state. The second I click the layer away, it's again super fast. It's doubtlessly caused by the markers being rendered.
Why would less than 3,000 markers even make it go slower at all? Even a computer from the 1980s would be able to display such a small amount of markers on a map, no? And more importantly: how to fix it?