we've had 4-2-3-1 for the past 6-8 years it's bloody awful, WHY are we still using it.
The premiership title has been won by teams playing 4-2-3-1. It's not as simple as saying one formation is good and another is bad. The formation is only one part of the formula.
The other part is the players - we have lacked proper movement off the ball for many years, and confident capable players who can and will move forward with the ball at their feet. We have traditionally left our CF very isolated and rarely had consistent, reliable performers at 10 or on the wings. Naismith had his moments as a 10, as did Mirallas out wide, but they were the best of what has been a bad bunch over the last decade. Sigurdsson and Richarlison are massive upgardes. Equally in CM we have recycled a lot of very uninspiring midfielders - Barry, McCarthy, Cleverley and the like are never going to beat a man and dribble forward at pace. Manuel Fernandes was the last CM we had who could regularly do that, and Barkley showed it in flashes.
Whilst trying to win the ball back we could line up in the 4-2-3-1, using Richarlison, Kean and Iwobi to pressure opposition defenders into making mistakes and giving up the ball... but if the three of them don't work as a unit to generate that pressure, it won't work.
Pickford
Coleman - Mina - Keane - Digne
Gbamin - Gomes
Richarlison - Sigurdsson - Iwobi
Kean
Once in possesion, the ball should be coming through Coleman, Digne or Gbamin to Gomes and Sigurdsson, who either carry it forward themselves or pick out players moving into space ahead of them. If it all slows down then one, or both, of Coleman and Digne move forward to get involved, whilst Gbamin drops back to shield Mina and Keane. If the players around the ball carrier don't make runs into space however, it won't work.
Pickford
Mina - Keane
Coleman - Gbamin - Digne
Gomes - Sigurdsson
Richarlison - Kean - Iwobi
There is no one formation that grants defensive solidity AND provides support for your CF. Your players have to move.