I'm not one to be pedantic but yes you won the Fa Cup six seasons ago under Van Gaal then in Mourinhos first campaign he achieved a Europa League and Carabao Cup double, which means you only reached won final in five seasons (2018 Vs Chelsea) and lost.
This together with the money you've spent means your actually not doing considerably better only slightly. Therefore Saka probably wouldn't view United as a destination to elevate his career.
You are not pedantic, you are just wrong. We won FA Cup in 2016. That’s 5 years ago and one of the last 5 seasons too regardless of how you try to spin it. We won League Cup and Europa League 4 years ago, it is also one of the last 5 seasons. So basically when you said we hadn’t won anything in the last 5 seasons, we actually won all of those things in that timespan. When you say ‘last 5 seasons’ you cannot possibly include the current season in that as nobody has won anything this season yet. For all you know we may still do FA Cup and EL double.
You made a wrong statement and now try to still spin it as right by saying something that happened 4 or 5 years ago was not in the last 5 years.
But yeah, if you actually exclude all finals we won in the last 5 seasons, then we lost all finals we were in. That statement is correct. Also, if you exclude all games in which Arsenal got points this season, you have actually lost every single game this year - that's catastrophic!