It is true that Arsenal has performed quite well under Arteta in the last two seasons. They succeeded in challenging Manchester City in the race for the Premier League title. Despite leading the standings for a long time, Arsenal always failed to win in the end. Like what happened last season, the Gunners were overtaken by Manchester City at the end of the season. However, even though he failed to get the Premier League trophy, Arteta has given Arsenal two trophies. They have won the Community Shield and FA Cup. Arteta has done his best for Arsenal but not for their fans. And I agree with your opinion, Arsenal does not have the winning mentality to win the Premier League trophy.
Arsenal as a whole has improved under Arteta leadership, especially in the last two seasons, Arteta squad was able to put pressure on Manchester City until the end of the season, But what is more memorable is that Arsenal was able to erase most people doubts by appearing more consistent, unlike the previous season, so that this season Arsenal is only 2 points adrift of Manchester City, Although Arsenal failed to win the trophy, I think Arteta has built the foundation of his squad very well, so next season their chances of challenging for the title are still very high.
Meanwhile, Arteta should be able to bring in quality strikers in the transfer market this summer, Jesus and Nketiah don't look so sharp, perhaps due to injury factors, if Arsenal have a sharp striker like Osimhen, I think their goal productivity next season will be even higher, as well as increasing their chances of winning trophies, but we know Osimhen seems to be getting closer to going to PSG, so Arteta needs to find another striker who is already experienced and tested, I think it was an instant way to smooth out the ambition and end the more than two decades of waiting for the title.