Privacy-friendly whatsapp

I know the title sounds like a paradox, but let me explain:

In Feb '21 I deleted all my Meta related accounts in a first step towards moving away from big tech. Removing whatsapp was kind of a big deal over here but I managed to get close family and friends over to Telegram and Signal and resorted to text messages with other contacts. I've been enjoying the peace and quiet but it's been a hassle for everyone around me. Invites to parties, big news or announcements always had to be relayed through somebody else. Last week a dear friend passed away and because that news had to be rleayed to me too i think its time to go back again.

And now for my question: is there a way to run whatsapp on your phone while respecting privacy? I know it sounds crazy but I was thinking there might be a way to run it in a sandbox or closed environment of some sort. Im running LineageOS on my phone and I dont mind tweakin around a bit.

Because I live in the EU i was putting my money on the DMA, it was my understanding that the DMA would make it possible to send telegram messages to whatsapp, whatsapp messages to signal and in this way get in contact with anyone on any platform you'd like. When the DMA went into action in the beginning of this year it became clear pretty soon it would only be a one way street; all messenger services would be able to contact whatsapp, because that is the biggest player. Half a year down the line and I havent been seeing any news about it anymore. Does anyone have an update? Will it ever be possible to chat crossplatform?