Lot of top teams with UCL would always have good 3rd and 4th choice CM and even competent 5th choice. 3 of the 4 teams below had at least 5 solid or competent midfield option while the team that didn't have 5 midfield ironically out of European spot now.
When Chelsea had UCL, they had Caicedo, Santos, Lavia, and Enzo. This season, they didn't need to have good squad depth as they don't have european comp.
Arsenal had Zubimendi, MLS, Rice, Merino, and Norgaard. And now they signed Bruno G.
City had Rodri, González, Reijnders, Silva, Kovacic. And now they signed Anderson to replace Silva.
Liverpool had Gravenberch, Endo, Szoboszlai, Mac Allister, and Jones.
While this season we are competing in UCL so we need better squad depth than teams that don't have UCL. We have Mainoo, Santos, and Tielemans only with trying to convince ourselves that we are going to convert Mount the Bruno's backup with bad injury record as our 4th choice midfield and our 5th choice is Fletcher. In comparison, the likes of Liverpool, City and Arsenal who are in CL have better midfield depth than us.