Not just the 3rd world (assuming you mean developing world, not the non-aligned movement). Ireland's national health service allowed the (already prevalent) use of WhatsApp during the pandemic (and which helped save it when internal email was taken down for months alongside almost all other IT services due to a ransomware attack). Now non-clinical comms is dominated by WhatsApp and the service would literally halt without it.

Source: https://healthservice.hse.ie/staff/procedures-guidelines/dig...