Manchester City's performances last season were somewhat erratic as De Bruyne and Haaland missed several matches due to injury. And these two players are the most important players in City's squad. This is why we saw Manchester City's somewhat erratic performances earlier in the season. But Guardiola was able to keep the team stable. Manchester City looks to be stronger next season.
Arsenal need a stronger squad if they want to win the title. Arsenal need a suitable replacement, especially after a player is injured. If not, the Arsenal team will not be able to survive in the title fight with Manchester City. However as a layman I expect the Premier League to be more competitive next season.
When De Bruyne and Haaland missed games due to injuries last season, Manchester City moved from second to fourth place, that is why I said that if Arsenal wins the League next season without signing more players to their team, maybe De Bruyne and Haaland are not able to play because they are key players in Manchester City. However, I believe they were not the only Manchester City players who always win games. But as De Bruyne was unable to play, Guardiola used Rodri and Kovacic to defend the position, to make sure the team did not lose all their games.
The next season will start in two months, and Arsenal are yet to sign any players to improve their performance. Arsenal needs top players to replace their attacking players when they are unable to play, even if they cannot win the game, they should not lose because that is how they lost some of their important games last season and their chances of winning the Premier League ahead of Manchester City.