The addition of two more teams ^{Chelsea and Manchester United} are ready to become contenders for the Premier League title in the 2023/24 season. Chelsea is more promising because the number of players they recruited signaled other candidates to be careful.
They have shown the game during the pre-season tour. Of the several Premier League top teams that are on pre-season tours, Chelsea is the team that performed well with the wins they got.

Don't think that pre-season tours are not important in measuring seriousness when official competitions take place, but pre-season matches can have a positive impact on many things to compete in official competitions.

IMO, the 2023/24 season has been more dominant for Liverpool and Chelsea.