The favorites to win the league title next season are Manchester City, Arsenal are in second place, followed by Liverpool, Chelsea, Manchester United & Tottenham. The league hasn't started yet, so we can't say that Kai Havertz won't do anything for Arsenal in the coming season. In the match against Bayer Leverkusen, he got the highest rating than anyone else, can't say anything, but it seems he has been quite consistent in the last 2 friendly matches.
Speaking of teams to win the league title and you included Man UTD (very laughable), Chelsea and even Tottenham? What is the assurance that Chelsea can even make it to the top 4 position of the log come next season? I don't want to say much about Tottenham Hotspur because we hardly see much from them and is like the pre-season games doesn't concern them in any way to rate their performance but I can say they may finish outside the top 4 like 5th or 6th but not Chelsea who have been all over the news with their poor defense and their poor selection of players in the transfer market.
Let's say Kai Havertz can deliver but what if injury comes in what are the plans to cover that open spot? Arsenal only recruit backnups for the midfield defense but not the wing and attack so what's going to happen if something went wrong? See the money Pep Guardiola got from selling Alvarez, I believe he has something big as a replacement for that deal and we'll get to see the surprise he has for every club in the EPL, even if he never got any player this transfer window I believe he must make sure the team is completely balanced, so I can't picture Arteta edging up with Pep Guardiola with this squad without a striker.