"only one" Indonesia airline (Garuda) is permitted to fly to EU countries.
Some have reached an international standard and are permitted to fly into the EU although I understand only one does at present.
Garuda , Mandala, Premiair and Airfast are the ones allowed to fly into the EU.
The majority of these operators have one thing in common - they have on-going contracts with major oil, gas and mining companies. It is these clients who are driving up the aviation standards, not the DGAC, and it is done by rigourous external audits and comprehensive contract requirements.
I have seen some of those external audits and they are not rigourous at all...just another way to make money...maybe the only reason why we don't see many non-scheduled operators crashing is simply because they don't fly as many hours as a scheduled Indonesian operator.