The bold is revisionism.
He was widely derided in the media, social media and by his own fans as being a fraud, BTEC Pep, too obsessed with crosses and out of his depth.
April 2021 - Worst record out of Wenger and Emery. Some in media saying they played like a championship side and many fans not wanting another season.
November to December 2021 - 7 league games without a win. Again intense pressure to sack him.
What he did do throughout his tenure is that he talked about culture and had Edu to help him bring in the right players and ship out the wrong ones even bigger names like Ozil and Aubameyeng.
It’s also worth mentioning that some of the most significant improvement in certain areas came from elsewhere. They also got in a new set piece coach in 21/22 season that meant they went from 6 goals from set pieces (17th in the league) to 16 (3rd) and after this appointment didn’t concede a set piece until the following April.
Arsenal are now one of the most dominant sides from set pieces in the league.
Yes the managers are responsible for lots and lots of things and sometimes they deserve the sack. Heck from the outside I would have sacked Arteta too. But when you look at the most recent challenger to City what they did was sort the footballing structure and culture out whilst giving Arteta the players and time to create the new culture and develop a successful team.
Even now though they still haven’t won anything greater than what Ten Hag has at United.