I'm not denying that major flaw of Signal, in which part, yes exposing your phone number tied to your Signal account basically negates Signal's security, as well as Signal's centralized server being proprietary. Nevertheless, when using Matrix, you need to ensure you and everyone you communicate with uses a client that isn't still using the deprecated libolm cryptography backend (and that it uses vodozemac).

Many Signal alternatives also have security issues of their own, often making them less secure than Signal. This includes Matrix and XMPP. In the blog post regarding XMPP+OMEMO, the author replies to a question about which would be better than Signal, Matrix, and XMPP with this suggestion:

Anyone who cares about metadata resistance should look at Cwtch, Ricochet, or any other Tor-based solution. Not a mobile app. Not XMPP. Not Matrix.

In regards to Ricochet, not having a mobile app version makes it difficult to recommend to less tech savvy people.

https://github.com/exander77/proton-bridge-android

There is a way to do it locally on an Android device using Termux.

Funtutu

Have you tried one of these providers? https://providers.xmpp.net/

I didn't have an issue with registration on macaw.me or monocles.de, but I haven't used those accounts yet.

I will be honest, I haven't came around to using XMPP myself yet, but I am pretty sure you are able to do all of those things, at least with the help of extensions. Here's the XMPP standards that are currently stable or experimental:

Files/Images:

• XEP-0363: HTTP File Upload [Stable]
• XEP-0446: File metadata element [Experimental]
• XEP-0447: Stateless file sharing [Experimental]
• XEP-0448: Encryption for stateless file sharing [Experimental]

Emojis/Stickers:

• XEP-0444: Message Reactions [Experimental]
• XEP-0449: Stickers [Experimental]

Looking at clients, I see various ones that have at least some of the features you are looking for (especially file and image sharing, I haven't found a client that has explicitly implemented the stickers specification yet, but Movim seems to have them):

• Converse.js
• Dino
• Kaidan
• Movim
• Profanity

I would give it some more time. It seems those features are in development, but this is essentially an alternative to Matrix that is more standardized. It's a widely adopted and integrated protocol, so I don't doubt the features you are looking for will become more fleshed out some day.

XMPP it is, then.

I have done so (git clone) with Gentoo and it works.

Then again, after learning about the crappy things the Raspberry Pi Foundation has done, I'm probably better off getting a used Lenovo ThinkCentre or HP EliteDesk Mini (which I already have) for a much lower cost. I was just excited about Raspberry Pi's finally being powerful enough to handle 4K, but that may be a stretch, too.

Whistles casually

https://github.com/pluja/awesome-privacy#instant-messaging

https://github.com/pluja/awesome-privacy#teamworking-tools

https://github.com/pluja/awesome-privacy#video-and-audio-conferencing

https://github.com/awesome-selfhosted/awesome-selfhosted#communication---custom-communication-systems

https://github.com/awesome-selfhosted/awesome-selfhosted#communication---irc

https://github.com/awesome-selfhosted/awesome-selfhosted#communication---video-conferencing

https://github.com/awesome-selfhosted/awesome-selfhosted#communication---xmpp---servers

https://github.com/awesome-selfhosted/awesome-selfhosted#communication---xmpp---web-clients

https://github.com/redecentralize/alternative-internet#messaging

Referencing my buried comment with suggestions:

I don't remember and can't find a post I saw in the past recommending better video chat applications for more than two users. I believe one was Jitsi and another Wire. I just found another video conferencing application someone recommended online: MiroTalk. Different open source software excel in different areas.

Sorry, I just realized this post is about instant messaging platforms and not specifically their video chat features.

I like Element better because of its Markdown capabilities (though still very limited) and the ability to edit messages. I used element for my team coding projects in college, which worked very well and integrated nicely with our GitHub updates, but it sucked for video conferences. Signal barely holds up for two-user video chats, though that could be my internet or someone else's.

I also want to self host my own XMPP server someday.

There is Revolt. Maybe younger people will like that more.

I don't remember and can't find a post I saw in the past recommending better video chat applications for more than two users. I believe one was Jitsi and another Wire. I just found another video conferencing application someone recommended online: MiroTalk. Different open source software excel in different areas.

Sorry, I just realized this post is about instant messaging platforms and not specifically their video chat features.

I like Element better because of its Markdown capabilities (though still very limited) and the ability to edit messages. I used element for my team coding projects in college, which worked very well and integrated nicely with our GitHub updates, but it sucked for video conferences. Signal barely holds up for two-user video chats, though that could be my internet or someone else's.

I also want to self host my own XMPP server someday.

There is Revolt. Maybe younger people will like that more.