Simplicity, E2EE, foss, cross platform support. Low hanging fruit for people to easily migrate to.

AFAIK simplex only works on a single device but the privacy benefits are great. Probably more tinfoil than most people need

Signal seems like a pretty good option to replace your default messenger/phone app but I don’t know how it compares to telegrams group chat features

I like Element/matrix but I’ve always had minor issues when self hosting. Mostly connection problems (probably my fault)

Haven’t tried 0xChat much so I can’t really comment