On Pointless - huge No1 hits by Moby (2000) and Miley Cyrus (2023) got very few people knowing them - all soundly beaten by Madonna, Madness and Marvin Gaye. Artistes beginning with M. Come on - nobody apart from fans has ever heard a song by Miley or Moby. Mass appeal this century? Dead.

I came with these within a minute or so.
Murray Head
Michael Bolton
Mott
Mountain
Magnum
Murder Dolls
Mushroom Head
Mr Big
Montrose
Mr Mister
Michael McDonald
Monster Magnet

I think if you asked anyone to name a Miley Cyrus song the top answer would probably be Wrecking Ball.
Must be her best known song.

Well I've heard the title Wrecking Ball but I've no idea what it sounds like and neither do I care to find out, so JK is quite correct.

The first time I realised that you could actually hit No1 without any genuine mass appeal was with Iron Maiden who hit the top spot displacing Cliff just after Christmas in 1990, early 1991, with Bring Your Daughter To The Slaughter, clearly a single that was only getting bought by the Iron Maiden fanbase in the immediate post Christmas sales dip. It was surprising it managed to hold the top spot a second week because it clearly had no mass national appeal other than to metal fans of Iron Maiden.

I'd also state that not one of the five No1 Christmas songs of LadBaby from 2018 to 2022 can seriously be considered meaningful authentic No1 hits.

I never got into Maiden but they are still selling out arenas and stadiums.

I think people bought the single just to get Cliff Richard off the top spot in the early 90s.

People streamed and bought Rage Against The Machine just as a "fuck you" to Simon Cowell.