I didn't realize so many people use a high pass filter or that that was even a thing. Something to ponder!
It caught be by surprise as well. It wasn't until I started using an amp with an onboard HPF that I realized how much it can extend EQing options. When something seemed boomy or muddy, I used to boost and cut EQ bands as the first solution. Now I start with the HPF to remove the undesirable lows and it frees up the EQ to tweak other areas.