Arsenal's principle not to spend a lot during the transfer season already changed since Kroenke has come. They would not be among the clubs that have spent a lot if they were still following Wenger's philosophy. However, it doesn't matter how much money they spent, but the same result as always.
Everything changed when Arteta came to Arsenal. By the way, his first season was a bad one because Arsenal were at the bottom of the table and only started improving their results after some time. The board decided to keep Arteta and allowed him to buy new players. Arteta has always had very big ambitions in the transfer market but as we can see it has not brought any results.
Arsenal have not been able to win a single title all these seasons even though they have been playing quite well especially if you look at the league and the Champions League last season. It seems like at times they show very good football but there is a problem because their performance always drops at some point. Maybe the reason for this should be looked for not on the transfer market but inside the team itself.