Started the season with 3 defeats in a row is indeed a bad start, moreover, Arsenal has spent 165 Million Euros to sign new players. However, they just got their first win in the Premier League, even though it was only a narrow win with a score of 1-0 but this win means a lot to Arsenal.
A team with a great history like Arsenal should be able to recover from their slump because they still have good players to rely on. For that Arteta has to work even harder. If Arteta can't fulfill the task, it means that the one who made Arsenal slump all this time was him.
165 million euros is a very large amount and indeed this season arsenal is the most wasteful team in bringing in players but the players with a very expensive price tag so far have not had any spurs given to arsenal to rise, even the current season is arguably the season Bad arsenal in the early matches because it is true what you say, with the depth of the squad that is expensive this is not worth the performance shown.
For example, like Ben White who was bought for 50 million euros but his current game is still far from performing at a price of 50 million euros and he often makes blunders both in passing and guarding opposing players.