Look, Americans debating whether ASEAN should be abandoned is just as ridiculous as ASEAN member nations debating whether NATO should be abandoned. It is not our place to dictate how those nations govern themselves. ASEAN was founded in 1967 to advance the economic and political goals of its member nations. It is up to those nations to determine whether or not ASEAN is doing so.
Critics of ASEAN declare the organization to be inflexible and unresponsive. Those critics may be correct, but even if those changes are true it does not mean that the organization should be abandoned. Sensible reforms would likely make ASEAN better able to serve its member nations. But in a global economy dominated by America, China, and the European Union it makes little to no sense for the countries of Southeast Asia to abandon the one organization that puts their needs first.
The ASEAN seems like it serves a purpose and can help those nations. I think that if there is widespread support for it and not too many issues arise from it than it could stay in place. It seems like it could be beneficial to these countries and help them.