I would say that the SEA Games is mainly a regional games, not only to promote sporting friendship and closer relationship among ASEAN countries in particular, but also to give especially the younger athletes a chance to test their skills. It should not be compared with the big ones like the Olympics.
It could be regarded as a gateway for young promising athletes intending to make a mark in the sporting arena, hopefully with the Asian Games and the Olympics as targets. There should be opportunities for them to compete among peers.
So the Games do serve a function in the interim years.