Reminder it makes sense for Leon (and Galar) to be strong:
>In Galar, each Pokémon type has a gym.
>Gyms are split between major and minor leagues, with the top 8 performing gyms belonging to the former.
>Major league gyms get to participate in the Champion Cup for a chance to take the title of Champion.
>Thus, major league gym leaders continuously train in order to defeat the Champion.
>And the Champion must keep training to retain their title.
>However, minor league gym leaders can challenge major league gym leaders in order take their spot.
>And thus, minor league gym leaders continuously train as well.
>This, along with Galar's competitive sports culture, encourages gym leaders (and thus, the champion) to become stronger and stronger rather than stay stagnant.
Other tidbits about Galar:
>Each gym leader is personally trained by Mustard, who used to be Galar's undefeated champion. This is the equivalent of Red training Kanto's gym leaders.
>Raihan is said to be so strong that if he were to move to another region, he'd become its champion.
>But despite that, he's never been able to beat Melony.
I unironically think this is a very cool system that can explain why Galar is so much stronger than other regions. I wish it were discussed more.
