I have no problem with selling Savinho. I don't really rate him but he is only 21 and can obviously become a good PL winger in the future. But we already have Marmoush/Foden/Cherki/Doku/Bobb/Bernardo capable of playing on the wings and all of them are as good as or better than Savinho in my opinion. I'm sure most agree we wont be winning trophies anytime soon with Doku and Savinho starting as wingers.
Hopefully selling Savinho would mean we can get another player in.
So far we have signed Reijnders (who is great), a "left back" from the worst non relegated defense in the league (who is exiting), an attacking player from Lyon who looks like a huge talent but is far from certain of being first choice, and a backup GK.
Thats a window thats decent if you have just won the league. It's not a very good response to the club having its worst season in a decade, when the ambition is to be the best in the world. In my opinion.