Like how LeetCode rewards users with 1 coin for daily progress/login, I think LeetCode should reward users for solving a problem too, May be with:
1 coins for solving Easy Problem.
2 coins for solving Medium Problem.
4 coins for solving Hard Problem.

This will not only help user to earn more coins but also to improve more user interaction with the platform. LeetCode may start seeing more users with more rewards.

I see same pattern of rewarding coins or xp for users on other Online Coding Platforms.

One other feature which I see missing in LeetCode is friends or connections section. I have few friends who are active on LeetCode, I wish to see their progress and they wish to see my progress. Having a timeline, which shows this data would not help in knowing my friends progress but also this may inspire me to do more problem solving.

LeetCode is the best platform from my perspective and I feel if it fills these voids, LeetCode will just continue to be No.1 forever.