I'm planning a trip in Southeast Asia for September.

I would want to be flexible on how many days I stay in each location & my plan was to book hostels for the first few days and then decide afterwards if I want to extend my stay / change.

I saw here many user mentioning they book Hostel a couple of weeks in advance, even a few days in advance, so I assumed this was not going to be a problem, but as I'm looking at Hostelworld some hostel seems to already getting full for September!

Is it becoming more common for people to book super far in advance now? Or do hostels reserve some availability for later in the season (faking scarcity to encourage more booking)? Should I look into booking my hostels now, or is it better to wait and hope more availability opens up later?

Any insights or tips would be greatly appreciated!

Thanks!