Legends are entertainers who get passed down through the generations, or conversely "do a Cliff" and try and stick it out through all the generations they are alive for.
Genuinely, and I follow music and film/TV quite closely, I can think of nobody, not entire band or specific person, that will be passed down like legendary people used to be.
Led Zeppelin STILL gets passed on from dad to son (and daughter) to this day, they are true legends of the past few decades, there is nothing like them anymore, everyone and everything is too throw-away.
There are some who want to become legendary, ppl like Jack White want to do it (but never will imo) and clearly Grohl etc wants to, otherwise them crooked vultures wouldnt have been started.
Honestly, people of my age reading this thread, which artists / film stars of today would you pass onto your kids by introducing them to the stuff because you like it, not because you think they might but you dont give a stuff about it? I'd be interested to hear what people suggest.
It's even spread to the world of sport, it used to be that football players were legendary, as were some racing drivers, but now? They are mostly over-paid yobs who rape good taste while making us all cringe and laugh in equal amounts. Legendary they are not. And legendary racing drivers?? The only one I can think of is Colin McCrae, and if im being brutally honest I'm not 100% sure i would have written that before he died (harsh but true).