That's because G Unit as a movement was a borderline fad compared to Roc-A-Fella and Bad Boy. The latter 2 movements were seen as legendary in hip hop and known for producing lots of classics while G-Unit was hot from like 02-05 then fell off a cliff both musically and commercially afterwards.
After 2007, G Unit was FUBU status and even people here in Queens were rocking with Lil Wayne more than 50 in his own borough. I saw that firsthand.
Business wise, 50 was doing alright until he lost the lawsuit to Ross. That really held him back. At one point, 50 was making Jay/Diddy/Dre level business moves but, after the lawsuit, he just became a TV guy which is cool but makes him substantially less money to bounce back from the bankruptcy.
The fact that 50 used to have a big mansion in Connecticut but, now, we don't even have a clue where he lives, kind of shows the falloff. Hell, based on Daphne Joy's testimony, I wouldn't be shocked if 50 is a vagabond who rents different properties.