I don't use WhatsApp, but I've noticed a similar trend more generally. I've got several Matrix group chats with friends and family I regularly post in, a handful of small to medium IRC channels with internet friends I've talked to for years, etc. It feels like Twitter and Instagram and so on are a lot less personal now, just curated posts based on the algorithm, and lots of people who've decided they're comedians. I even will link an interesting post from a social media site in a group chat pretty often, but don't interact with the people from that chat on social media platforms themselves.