Then your next best bet is Matrix.org. Not to the same security standard as Signal, but if you don't have a specific threat against you then it's fine.
Pros of Matrix: it actually has a consistent history (in theory); no vendor lock-in.
Cons of Matrix: encryption breaks constantly. Right now I’m stuck in a fun loop of endlessly changing recovery keys: https://github.com/element-hq/element-web/issues/31392
Pros of Matrix: it actually has a consistent history (in theory); no vendor lock-in. Cons of Matrix: encryption breaks constantly. Right now I’m stuck in a fun loop of endlessly changing recovery keys: https://github.com/element-hq/element-web/issues/31392