One option would be to increase the friction of the platform to 1 and the player’s one to high enough value. To eliminate the slide completely, you need them both to have friction at max 1. But then your player will not be able to move. After all, its a simple capsule that just slides on the ground surface. If both the ground and the capsule will have max friction - no sliding will take place.
So, you want the player to not have a maximum friction and allow it slide. But then that means it will slide on moving platforms. What can help is you can reduce the speed of the platform, so that it would not be enough to slide the player, but would still move. Another option, is to not allow a player to move while on platform - this can work only in some gameplay scenarios, while not suitable in others.
The best solution would be to build a local physics grid around the moving platform, and simulate the player in the local grid. The player would then not slide, since it would consider the world is stationary. This might be hard to implement, though, as you’d need to manage moving the player from world to local grid and back.