Upgrading my bike drivetrain - help!

I have a 2016 Felt F4X bike that I run as a gravel/road setup (1x11 spd). It currently has Rival 1x hoods and RD, with a Force 1x crankset. I have two identical sets of wheels, built on DT350 hubs that I swap out, one with gravel tires (XDR driver with SRAM cassette), the other with road tires (shimano 11spd drive with shimano cassette) for training. I'm considering upgrading the transmission and a bit lost on the best path forward. Looking at a SRAM electronic setup, but that would likely require me to upgrade the crankset as well?, and would require two new cassettes (possibly drivers for the wheels as well). I'm trying to stay under $1k. Do I go AXS mullet, full AXS, possibly look at Shimano? Hit me with ideas!