Haha we are talking about Arsenal in the last 3-4 seasons when they were close to winning the title but it seems the curse is still around 
I won't underestimate Arsenal because I know they have the ability but somehow they have to compete with other great teams who are constantly improving their squads. On the other hand, we are still waiting for Arsenal steps in this transfer window. because it is impossible for them to only rely on last season's squad while as you said Liverpool and Manchester City have already brought in new players.
There is almost no formula that can be explained with certainty why Arsenal failed to win the Premier League even though they dominated the previous three seasons at the start of the league. Next season will be much more difficult if they only rely on strength like last season because Liverpool and Man City have made changes by bringing in a number of players to complete positions that are considered quite weak. I won't underestimate Arsenal because I know they have the ability but somehow they have to compete with other great teams who are constantly improving their squads. On the other hand, we are still waiting for Arsenal steps in this transfer window. because it is impossible for them to only rely on last season's squad while as you said Liverpool and Manchester City have already brought in new players.Arsenal management needs to make efforts to make Arsenal's chances of winning the Premier League come true and maybe the most crucial thing is bringing in an attacking line so that next season they have a differentiating figure. If Arsenal does not take this opportunity then I doubt that next season they will be able to compete with several other strong teams.