WhatsApp is fine IMO. It's really just an instant messanger that does about as much as any other. In terms of privacy, WhatsApp is far from bad compared with other apps. The fact that Meta own WhatsApp doesn't really impact that too much.
I just try to avoid tiktok. I'd use it if it wasn't basically Spyware, but its literally got backdoor access for an authoritarian country that keeps saber rattling. Id rather use snapchat and I definitely don't want to use that either. Its shame.
Social media is being decentralised the same way Lemmy is. Platforms such as Friendica, Pixelfed, Mastodon, etc are all platforms for decentralised social media.
I envy you, I pulled some family members from Facebook messenger to signal when I closed my account, and while I don't trust Meta keeping WhatsApp private, its still better than Snapchat, Messenger etc.
My close friend groups almost exclusively uses it for communication, as much as I'd love to ditch the app, I'd then miss out on vital communication, I've tried to onboard them to Signal or Session but they won't budge, so I have to make do.
Try Matrix. It's a hair more complex than Signal but it has a lot more features- closer to Discord than Signal. Beeper.com is based on it- when they finally open the registration floodgates that will probably be the one to use. It's just Matrix (fully federated) with hosted bridges to a few popular chat networks. And that integration is enough of a 'carrot' to persuade a lot of people to move.
Signal is extremely viable got chats, voice/video calls and stories, almost 1:1 with Snapchat, only problem is no one wants to move, because theyre too comfortable with what they use, there'd need to be a mass walkaway like Reddit just had to get most people to budge.
This reminds me of how I have no idea what chat apps to even try to use with folks anymore. I know I personally don't want to use any Meta products, but that's what a majority of folks seem to use outside of texting.
Then there's Snapchat, which kinda sorta works for chat but it's not great since that's only like half its focus, with the much larger half being the snap part for sharing photos & tossing together videos.
I'm in the same boat. It freezes and crashes all the time on my phone. Been using it for so many years now and it's never really improved. Wish I could move all my group chats somewhere else, but there's no chance