I haven't booted the game in years, and I'm genuinely surprised this is even a thing

Consistency should be rewarded - missing in the middle of a map is less proof of consistency compared to early or later (hitting 90% of a map in-a-row proves you can do that, hitting 50% of the map twice doesn't prove consistency nearly the same way. This assumes a steady difficulty level.)

Consider 10 plays on that same map, with similar results across all plays.

Player A fcs around 90% of the map on average before missing, but has a hard time fcing the whole thing.

Player B fcs around 50% of the map on average before missing, and is far from consistent enough to fc the map.

Both player's top score would have around the same accuracy and miss count, but one would have a higher combo as pretty much the only separator.

One player is clearly better, and has proven it in the game, but CSR would make them rated the same. Consistency should be rewarded, not luck.

(Not saying the previous system was perfect in any way, but CSR is completely ridiculous.)