Think it all stems back to Sex on Fire. It rocketed them into becoming a headline act without them having developed a stage persona. People were just waiting for that one song to flip out to so weren't engaged in the earlier stuff and the band aren't the most engaging so it just became a meeting or the bored and the boring.
Agree they've improved since Covid - really enjoyed them at Sziget in 2022. I think them playing Sex on Fire early on in their set helps too - everyone waiting for that just clears off.