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.
Arsenal have always been close to winning the premier League trophy but always flop along the way. I think if Arsenal is serious,they will beat Manchester City and Liverpool over it. It all depends if Arsenal is ready and can put away their laxity behind,I believe Arsenal can still make a difference in pursuit of the premier League trophy next season. With the kind of close chances Arsenal have had before in previous seasons,one can say Arsenal had what it takes to win the premier League but couldn't utilize their best chances very well and that's what has rob them of becoming champions of the premier League.
Mikel Arteta should work on his squad very well to prepare them for what's is ahead because next season will be tougher and more competitive than usual,so Arsenal need to get prepared on time.