Drilled holes or mesh

[Dedenne]

Hello! Me again with more stupid questions!
I have been looking at making a transport box of a plastic box I have laying around if it happens that I need to take Missy to the vet or something (and buying one seems unnecessarily when I have this box that is the perfect size already) and realized that I do not really understand why people use mesh when building bin cages that comes with a plastic lid. Why not just drill a lot of holes in the lid and use it like that?

If you make small enough holes that covers the whole lid and some around the top edge of the cage (you can see it if you google bin cage) the ventilation should be almost the same. You can probably even make just slits like in the habitat eco on zooplus, just smaller so the hamster cannot escape. The thing I can think of is that the hamster might start biting in the holes and get out but for that it needs to reach in a way so it can start biting it and a lot of people use bin cages without any lid at all and it would take some time so It should be obvious before it gets too far.
I must have missed something