I will not totally agree with you that Arsenal and Arteta failed. Arsenal finished second in the league which is a fit they last achieved ways back. Arsenal not being able to win the English Premier League does not mean that they failed.
Arsenal is in the Champions league and they played good football last season.
However, I agree with you that Arteta contributed to why Arsenal could not win the league. He kept using the same players for all the matches when there was Trossard, Nketiah, Nelson and the rest of them that would come in for Jesus and Saka in some matches.
Manchester city won the race to win the English premier league title, I figured out that Pep Guardiola knows how to beat his preeminent rival to win the league. Arsenal missed out big time on lifting the English premier league title, although it's caused by relenting efforts. Mikel Arteta didn't failed the club, taking them to the UEFA Champions league after a lengthy period of time. I believed they will bounce back to glory ways, and this time, they will win the significant trophies and sign more big names that will served essential contributions to the growth of the club.