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.