Arsenal are a side who have made mistakes in the transfer market over the years. Overpaying for players, paying them too much and breaking the wage structure or simply not moving for a profile who pushes the needle forwards.
To reach the top, a transfer theory emerged which was used to measure whether a player was the right move to make to see progression in the group. To be like the best, you have to sign the players who the best would also sign.
With both Manchester City and Liverpool the two sides at the top for so many of the past few years, when Arsenal would look to sign a player the rationale would often be would either of the title-challenging pair also sign them. If not, why make the move?