It is a simple footballing logic that when players move to better clubs and play alongside higher-quality teammates, their performances often improve.

A clear example is Mohamed Salah. During his time in Serie A, he recorded goal tallies of 9, 15, and 19 goals across different seasons in all competitions.
However, upon moving to Premier League and joining Liverpool, his numbers significantly improved. In his first season, he scored 44 goals, followed by 27, 23, 31, 31, 30, 25, and 34 goals in subsequent seasons.
Softfootball notes that it is only in the 2025/26 season that Salah’s performance levels have dropped compared to his usual standards. His highest tally in Serie A was 19 goals, which raises an important question—does this mean the Premier League is less competitive than Serie A?
The evidence suggests otherwise. Salah’s improvement is largely attributed to moving to a better team environment and reaching his prime at Liverpool, rather than the difficulty level of the league.

A similar pattern can be seen with players like Luis Díaz and Michael Olise, who have thrived after moving to Bayern Munich. Their performances have improved due to a system that suits their style and the quality of players around them.
Overall, player development and output are often influenced more by team structure, tactics, and supporting cast than by league difficulty alone.