Previously, Arsenal also had some good recruits, but still, they still couldn't do and get the best results. It's not easy to compete in the Premier League, but Arsenal has the same pattern, their achievement is "close to win the EPL, but again failed." and this has happened for years.
PL is not an easy competition, that's why Arsenal has struggled to win the title for years, we know that the other 2 teams that are very serious in the race are Manchester City & Liverpool. I think there's only 1 chance for Arsenal to win, which is the slump (decrease in performance) of the 2 teams, if Manchester City & Liverpool have a bad season, I think we can seriously consider that Arsenal will win the PL title.
It is true that the Premier League is a difficult league, but that is not the main reason why Arsenal has failed to win the Premier League title in a long time. Arsenal has been able to improve their performance in the past 2 Premier League seasons and this season, and they were close to winning the Premier League title in those seasons, but Arsenal always struggles to perform well at the end of a season, which gives either Manchester City or Liverpool the advantage to overtake Arsenal in the Premier League table and end up winning the Premier League title. Arsenal doesn't need Manchester City or Liverpool to perform poorly before they can win the Premier League title. If Arsenal can stop giving their rivals the opportunity to top the Premier League title at the end of a season, I think Arsenal can win the Premier League title.