I'm wondering to which extent this effect can be attributed to illusion of competence, i.e. with age some meta learning program in our brains that is concerned

I'm wondering to which extent this effect can be attributed to illusion of competence, i.e. with age some meta learning program in our brains that is concerned with managing novel data simply becomes lazy because (1) adults really are able to handle most of the situations they are confronted with and (2) they are also expected to be able to deal with any situation. That might simply lead to a detoriation of the sort of novelty detection. Adults tend to automatically explain away things they don't understand (possibly to save face) while the young examine them. With increasing age these kinds of automatisms might simply override or detoriate learning strategies that are required to learn quickly.