I don’t feel it’s safe since it’s always open.
Plus I have buds off other brands end I like to keep cases on them too and they are of different sizes.
I think if you add a zip it will be secure and you can even use the pouch for other small things like air buds of different sizes or with cases, coins/cash, keys, lighter, sanitizer, etc essentially making it a quick access pocket.
I think you get the point.
Conclusion: Tried keeping my air buds in it but don’t feel they are fully secure with the zip it can be multipurpose and also secure