Element has been working with Meta since the end of last year to help test their DMA interoperability (given we’re probably the world leader in interoperable end-to-end-encrypted communication) - and Matrix announced last month at FOSDEM that Element has successfully integrated 1:1 chats between Matrix and WhatsApp via the DMA APIs, while maintaining end-to-end encryption (having implemented full Signal compatibility in vodozemac). We’ve also formally requested interoperability with WhatsApp, as of yesterday.
Just immigrate.