If you go to each show's gross page on BWW, it indicates that Phantom has an all-time gross of $1,310,379,968, while Lion King has an all-time gross of $1,788,077,255. So yeah, Lion King has grosses more.
Phantom has been running about 9 years longer than Lion King, but remember that the duration of those 9 years, ticket prices weren't even close to what they are today. And while Phantom has been pretty successful in the past 25 years (the length of Lion King's run), it hasn't been packing houses at top-dollar prices the way Lion King has. So with (a) all that success, with (b) a long runway to catch up, and (c) ticket prices much higher than they were during Phantom's "head start," Lion King was able to catch up way back in 2012
https://playbill.com/article/the-lion-king-takes-phantoms-throne-as-highest-grossing-broadway-musical-com-189258