Currently you can only set each conversation manually to be kept (with too many clicks anyways) - otherwise they will delete themselves after 90 days. I think it would be beneficial to have a setting to reverse this - so all conversations are kept & you only delete them manually.

I am sure this is stuff for the appropriate place over at reddit, so you'd better be fast! ;-)

Why do conversations get deleted after some time automatically?

So... after some time it will just fade into nothing? Why is that? Can't I archive at least conversations?
Is this Snapchat?
Did I miss something?

Edit: added screenshot