The 433 is the best system in football because of how tactical flexible it is, you can instantly switch to almost any formation without making a sub, because technically the 2 of your CM should be able play a 10 if needed.
As we see with PSG the way the switch positions all over the pitch, but especially in midfield is why I said since last season they are better than us, the only player we have in our Midfield with that level of flexibility is Pedri & gavi at his best, which isn't surprising, given that they are both Spanish & 1 masia
See the way Ruiz, merano, zubi, rodri, all those guys can switch and feel comfortable in at least 2 positions in Midfield.
It seems olmo left Spain to Early before his Midfield education was done.
One of a few key reasons, could give 10 more, PSG shows a lot of them