When running a full catchup ( what you’re doing ), you’re validating each block against its predecessor. That’s quite a cpu and disk intensive process if you have a long running network.
When you want to start off with a non-archival node, you don’t really need the entire history. You only need the recent 1000 blocks as well as a copy of the accounts state.
Catchpoints labels are the hash of that state. They allow you to use the catchpoint catchup ( sometimes referred to as “fast catchup” ), which does the exact opposite - rebuild the hash from the data, and make sure it’s matching your expected hash.
If you’ll ever need to want to catchup another node, you don’t need to trust anyone - you can use your own archival node that already calculated the “correct” catchpoint label.