In the past 3 Premier League seasons, Arsenal has finished in the second position of the Premier League, and Arsenal was very close to winning the Premier League title twice, but due to Arsenal's habit of always giving their rivals the chance of overtaking them at the end of the Premier League season, I think Arsenal not bringing in the right players is not the reason why Arsenal is finding it difficult to win the Premier League title because Arsenal has the right players already. Mikel Arteta has built up a good squad for Arsenal that can challenge for the Premier League title. If Arsenal can eliminate the habit of always giving their rivals a chance of overtaking them at the end of the Premier League season, Arsenal can win the Premier League title.
I agree with your idea that Arsenal problem is not about having wrong players but they are thinking how they finish season. Finishing second twice recently shows team is really good and Mikel Arteta has built strong squad that can compete. However their tendency to let rivals catch up late in season is key. This could be due to pressure or not changing tactics enough or just needing more experience in tight title races. To finally win Premier League.Arsenal needs to fix this habit by becoming mentally tougher and rotating players better and and learning from past close calls. Talent is there they just need to perform consistently in crucial moments.