The point of participating in a recital is not to proof you're the greatest pianist in the world. I don't need to compare my playing to other people as long as my piece is original enough at any level.
I don't like competitions where you classify people by age groups or other criteria than levels of playing. A while ago the main broadcast station CBC in Canada hosted a Classical piano online competition 2 years in a row. Each contestant would submit a video of their playing on an acoustic piano (no DP). The top contestants would receive a prize and the #1 would get the chance to play with the Toronto Symphony. Listening to the performers, there are people playing advance pieces flawlessly and students still trying to perfect "Minuet in G" from the Bach "Notebook for Anna M". Going by the pieces they submitted, anything at a lower intermediate level would not make it to the top 5.
In a recital we want variety. In a competition if we allow people who plays "Mary Had a Little Lamb" to enter, we should have an absolute beginner category so that those at a very low level can still win prizes. We don't want someone playing an early Mozart Minuet to be next to someone playing Liszt "La Campanella" because the latter piece is much more advance.