@Massimo ********
No they are not. Thailand: one day quarantine, PCR test next day, self test 5 days later. Entering Thailand is only possible:
a) by air, rules see above
b) by sea, more complex rules
c) via land border if you life close to the border and work in Thailand
No idea about the other countries you mention. My Vietnamese friend here claims that Vietnam's borders are more or less completely closed. Did not check it, so :P