@Goffi integrations like Instagram, Telegram and WhatsApp mostly rely on libpurple plugins (like purple-gowhatsapp or purple-instagram) that are either poorly documented, more unstable or lack many features that are available on Matrix bridges.
By own admission of some of these developers, they usually don’t test their plugins against Spectrum2, and mileage may vary a lot. And usually when one of these plugins dies it takes the whole service down with it.
I’m in general a bit unimpressed with the state of libpurple - I feel like it’s becoming a very aged ecosystem maintained by a very limited number of developers that have to make those plugins work for a very wide range of clients. That’s also the reason why I left bitlbee.
Slidge seems to be promising, but I feel like it’s still at an immature stage.