With just under half the games left to play this season, I think the next few matches will make it clear how serious Arsenal are, let's look at their consistency. But don't forget about Liverpool too, they are very strong now and will fight for sure, since they managed to secure the first place even in the middle of the season
Arteta doesn't want to learn from the past, last season they had a good start but in the end many players were injured so they were overtaken by Man City and this season Arsenal looks like they will repeat the same thing but not because their players are injured. but because they don't buy players. so they don't have enough players, let alone goal-hungry strikers. Arsenal played well but still had difficulty scoring goals so it would not be surprising if they dropped to fourth place in the standings in the middle of the season. From the start of the season until the Premier League started this season, I was actually not sure that the Arsenal squad could win the EPL.
This month there has also been no movement from Arsenal to buy players. I suspect it's not that Arsenal doesn't want to buy players, it's just that they love the money plus the danger of being subject to FFP sanctions. So I am pessimistic that this season Arsenal can become EPL league competitors because they cannot be consistent with the current squad.
I think Arteta has learned from his mistakes last season, but maintaining consistent performance and top results in the Premier League is very difficult. Arsenal are favorites for the title this season, but they are no better than Liverpool and Manchester City.
Arsenal has 18 games remaining in the second half of the season to try their luck at winning the title. I'm sure Arteta admits it's difficult, but nevertheless nothing is impossible for them and some other teams. The opportunities are there, it's just how they take advantage of them.