Whatsapp is under the same rules and has said they'd leave too.. https://www.theguardian.com/technology/2023/may/08/whatsapp-could-disappear-uk-over-privacy-concerns-ministers-told

But although it's popular it's nowhere near everyone using it.. I have about 2 whatsapp contacts and one of those is a mailing list. Most people I know use FB messenger. A few signal.. It really depends on who your friend groups are..