Actually, I was using gparted yesterday! I was trying to format a USB drive to exFAT but the option was greyed out, so either gparted doesn't have support for formatting in exFAT or I needed an optional dependency.

Ext4 with LVM.

I like BTRFS and it's features but sadly Debian doesn't have a preset for it in it's installer so the only way to use it is to manually partition and I absolutely suck at that.