Arteta is right about everything he says. Arsenal haven't been much near it since the beginning of the season. As of this loss the gap with Liverpool is 8 points so here we are.
The problem is that they don't have many players left who can score. Saka is out for months. Gabriel Jesus isn't even expected to recover before the end of the season. Who will play as the striker really?
They desperately try players like Havertz (he is also out), Merino etc.. They aren't even strikers. I know Liverpool also doesn't have a good striker but they have Salah who takes a huge responsibility in most of the goals.
There is nothing wrong with the composition of the players fielded by Arteta, he has tried to field his best squad but indeed in football there are things outside that change everything.
This week was actually a good opportunity for Arsenal to be able to cut points from Liverpool who are at the top of the standings but they failed, and that opportunity will not come again so I think everything is over for Arsenal.