I have a few questions such as:

I have heard a few rumors about Pokemon Trainers becomming Stronger.

Is it true that:
1.When you did 5x a VS Seeker battle against the same guy that his pokemon get stronger?

2. When you defeat the Pokemon League 20x Pokemon Trainers become Stronger?

Please Discuss and tell me if it's true or not, if possible could you give your own experience (if you had any) in these situations?

Thank you!