Always Be My Baby has 30M streams on Spotify (no Madead song does), it's Platinum in digital US sales, has good recurrent airplay, and even Fifth Harmony sampled the song. It's one of the most recurrent 90s hits in US.
It was a flop globally though, so I don't think it'd be a global classic.
Yeah...? Madonna is obviously not one of the artists that is gonna be heavily streamed, the streaming millenials all think she's a BDSM messy grandma.
TBH... She's seen as old and uncool. Being seen as uncool is worse than being irrelevant (you can still be cool and be irrelevant.) amirite or nah haha