Europe is in a weird middle-ground where WhatsApp is still dominant for person-to-person messaging. Not only was SMS costly back when WhatsApp emerged, users are also split 50/50 between Apple and Android, and SMS between them wasn't nearly as good as Whatsapp for the longest time. But WhatsApp Business is not a big thing. Of course that's vastly overgeneralizing, local differences exist, Europe is a big continent. But I mostly see SMS for transactional messages, and platforms like Instagram DMs for actual two-way communication

Interestingly enough, Instagram has none of this weird pricing stuff on their messaging API, despite being run by the same overlords