Battery adds significant weight. The mxMaster weights almost 50% more (141g vs 97g) than the wired mouse I use (Zowie EC1, NOT a small mouse, it's like the glorious old MS Intellimouse)... and the 97g is counting the cable.
Also, from my experience USB-C likes to giggle itself loose under really energetic movement.
The Logitech G Pro X Superlight is 63g and some of the newer wireless mice are coming in at under 50g.
It's now very unusual to see a professional FPS player using a wired mouse. The performance is indistinguishable and for most people, charging is less of a nuisance than cable management.
Also, from my experience USB-C likes to giggle itself loose under really energetic movement.