It's because we're going after top class players whose clubs generally don't wish to sell. Liverpool don't shop at the top of the market like we try to. Bayern also are pretty cheap and don't buy stars.
It's not exactly hard to get Fabinho out of Monaco.
That's not a bad way to go though. OF course, there will always be that marquee player want to sign which takes it's sweet time, but every transfer window we seem to have sagas, chasing players we can't get, etc. Umtiti was one of the rare signings we made that was cheap and came out of the blue, and coincidentally, worked too.
What I'm trying to say is that quick signings, even if they aren't big star players as such, shows that the management is planning and has foresight and working through the season on targets with a clear plan. Too often with us it seems we are making reactionary purchases, and last minute scrambles, and we often have to overpay because of this. It would be nice to know that the board has a clear plan, but maybe that's expecting too much from this board, which we know to be shit.