I don’t think you’ll have any luck persuading the Carto contributors to remove exit labels. In general it makes sense to show exit numbers at these zoom levels. Here you have an unusually high density of exits here, and with any form of automated cartography, there’s going to be the occasional ugly result.
You could easily hack your own version of the Carto style to suppress exit numbers, but deployment can then be a problem.
Frankly your best bet is to find an different source of tiles you can link to QGIS.
The Trackstack Topo map is a lot cleaner in this area. It only seems to be showing a random subset of the exits (which I find odd). Not so useful, but perhaps prettier.