If anything 60hz monitors benefit far more. Variable refreshes becomes a nonissue if your refresh rate is high enough that just waiting for the next frame isn’t too long. The case that benefits the most is when a game is running just below 60 fps on a 60hz screen and missing frames regularly, causing lots of stutter where it has to wait for 16ms. It’s a much smaller issue at 144hz since a delay of 7ms is relatively subtle.

fluctuates*

Not really. Monitors do poorly at lower refresh rates (anything under 50Hz, hence HDMI2.1 for example only doing 48-60 on 60Hz but on a 120Hz it can use LFC to multiply lower framerates). If you drop to 47FPS on a 60Hz VRR display you lose VRR or get other issues (flickering, persistence, etc). If you drop to 47FPS on a 120Hz VRR display it doubles it to 94 and you’re still smooth.