I'm not clear at all what this does other than help a bit with privacy and or anonymity to set up a full Bitcoin node so I don't have to trust my information to come from Ledger Live from what little I do understand is that's basically what it does changes the source of information for Bitcoin to the source?
Ledger Live gathers the whole
bunch of data which threatens your privacy and being connected (on default) to company's server sends this bunch to analytic company.
Thus connecting it to your own node (like Bitcoin Core) ensures those data will never live your computer. The instruction on setting up the LL - Bitcoin Core - working tandem can be found
here.