I do the same, gently. A child develops self-esteem by successfully doing something they didn't think they could do or seemed too hard for them.
I've tried to expose them to non-academic areas where they can experience this as well.
For DD8 it's been piano and swimming. Piano was never difficult for her, but swimming was VERY hard, still is. She amazes herself each time she drops her time.
For DD6 it's violin. She started at 4, trust me, she wasn't going to "instantly" get it. She wanted to quit a few times but I wouldn't let her because I could tell she wanted to quit because it was hard, not because she didn't like it. Now she's playing well and learning to read music. She loves the learning to read music part. Also she has a low frustration tolerence. I've been helping her at home with this for over a year. Trying to teach her to self-soothe and calm herself when she gets very worked up. This is very difficult for her and slow-going. But both of us see her progression and I think this is very empowering for her.
DD8 tried several sports that she reported were too hard. I did let her quit because my gut told me that it was physically too much to expect. When she found swimming, it was she who pushed herself to learn. It was a nice thing to watch.
