Those who apply in neighboring countries - like Laos, Malaysia, Cambodia etc - are most likely those who are already in the region (which is kinda the whole idea of remote working). Had they still been in their home country they probably would've applied there rather than going to the Embassy in Vientiane. Hence asking for an original physical stamp from the bank is an overkill considering the logistic difficulties of getting one remotely. A printout should be enough and some banks allow to authenticate the documents electronically.
While its possible to create a fake clone app of a banking app it'll likely be way more complicated than creating a fake statement printout with a fake stamp. Especially if one was to create a functioning app where you can click around etc.