This is another FIFA video game export, the idea that players are done at 30 only exists because they get significantly worse in the game at that age.
Fact is most of these guys will not change for 2/3 more years.
Real Madrid just won a double with Benzema (34) Modric (36) Kroos (32) Casemiro (30) Carvajal (30) Alaba (30) Marcelo (34) Nacho (32) Hazard (31) Courtois (30) Bale (32)
Liverpool's squad planning looks fine to me. Konate has come in and become 1st choice partner to VVD at 23, Alexander-Arnold is 23, Elliot (21) and Jones (19) are getting loads of game time, Dias and Jota are 25, they just bought the Fulham kid who's 19 and meant to be excellent.
Their time as competitors at the top level will end when Klopp goes.