If none of Liverpool's elite players leave the team this summer, they can maintain the pressure and do something good next season, if some of their elite players leave the team, there will be problems because Arne Slot will have to sign more players to balance his squad and the season will not wait for them; therefore, it will be better to sign new players before the beginning of the season, and you know that Manchester City, Arsenal, and some teams will compete for the title again next season.
Even if there are no key players leaving Liverpool, it doesn't guarantee they can maintain their game level and are still competitive as the previous season. The new coach may change their tactics or strategy. Also, the coach may change the formation and change the player in the main lineup. This potentially changes the game style of Liverpool for the next season. We don't know the change can bring a positive result or even a negative result on the team performance.
So far, I don't hear a big plan from Arne Slot to sign certain players. In the last season, Liverpool has a problem in the striker position. Darwin Nunez could play as expected, Liverpool has no strong striker. I think Arne Slot needs a stronger striker, Liverpool can try luck by negotiating with Napoli for signing Osimhen. Or targeting to sign local strikers such as Alexander Isak and Ollie Watkins.