The other problem with running pressures low enough to emulate proper suspension is self steer which can be pretty terrible with certain tires. I can't run below 8psi in the front because the handling gets really weird below that but I'd need around 5 - 6psi to properly take the hits up front.
In our rooty rock gardens I got fed up with bouncing around constantly and got a Manitou Mastodon Pro EXT. It has now 140mm travel and I could not be happier. I can now confidently ride even the most technical downhill sections as long as they're not too steep (don't have a dropper yet and I'm not a fan of stopping + adjusting my seat height every time there's a hill).
I'm starting to think the front suspended fatbike might be the mountain bike to end all other mountain bikes (for me). But if the frame ever breaks I'm going full squish. Having suspension in the rear would make the fatbike a monster.