We are fundamentally lacking two skillsets from making the system click.
We play with 2 x 8's in an inverted pyramid midfield. Every successful version of that midfield had two creative 8's in the role - Gundogan and De Bruyne, Xavi and Iniesta, Kroos and Modric.
We don't have that - our midfield best resembles Chelsea's midfield in 04-06 which had a ball winning 8 and a creative 8. Essien and Lampard. That midfield worked because they had two dribbly wingers who could consistently beat their men, so there was no real need for two creative 8's. Also, they weren't intent on playing in the opponents half forcing the opponent into low and mid blocks where creativity becomes even more paramount.
If we had two creative 8's, Odegaard and say Wirtz. Martinelli's complete inability to beat his man would be less of an issue because his movement off the ball could better be utilised. However, with us having only 1 creative 8 and on the opposite side, the lack of creativity from Rice and the lack of effective dribbling from Martinelli means that we are so ineffective on our left when building attacks.
This isn't new to anyone but it's the single biggest issue we're facing. Havertz and Merino haven't been creative 8's either and Martinelli is just not good enough for the level we strive for.
Either you sign a dribbly left winger who doesn't need a creative passer next to him or you sign a creative 8 and move Rice further back - but that looks unlikely with Zubimendi arriving. I've watched enough of Gabi now to say that he's just not going to be the player we want on the left. I struggle to think of any left back all season that he tormented and consistently had the beating of. We are desperate for a left winger who is on a similar level of Saka or better or you sign a creative player who is as good as Odegaard or better and can share the creative load.