There are a lot of reasons for each of those will try to provide some at a glance:
SimpleX, XMPP, Matrix: The client is more user friendly, less buggy and less "this is for nerds" UI than the clients of those networks, ArcaneChat is more on the WhatsApp-like UI
Signal is centralized, depends on phone numbers so can't be used by children in the family that don't have access to SIM card yet etc. Registering in Signal is also more complicated, SMS verification, solving captcha etc. No good multi-account and multi-device as ArcaneChat.
Groups in ArcaneChat are managed independent of the server while in XMPP they are created on a given server and if the server dies the group is lost, while in matrix a lot of group state is replicated and tracked by the servers, in XMPP is easy to end up with unencrypted groups and in Matrix you often get "unable to decrypt" and emoji reaction are not even encrypted, ArcaneChat groups are always encrypted and safe against MITM (green checkmark displayed in the group name)
ArcaneChat has in-chat mini-apps that work independent of any server, communication is only between chat members and e2e encrypted, for example collaborative editor in chat, shopping list, split bill app, several mini games with shared scoreboards etc.
ArcaneChat works offline-first unlike many(all?) of the previous mentioned apps you can even create groups while being offline use and modify the in-chat apps and all state will be synchronized when you are back online. The app also works in slow and unstable connectivity when most of the other mentioned apps would simply not manage to connect.
Element and Element X (curenntly using) are indeed buggy and I can xo firm that much. The sign-up and verification is, tbh anti-user, it's an intransparent process with too many steps, too many pitfalls, and the ecosystem is never gonna gain traction with this as a flagship experience. Element X is sadly not doing better overall. The constant red or black or grey shield over each message, which one can never get to green somehow? Three kinds of verification codes/mechanisms to understand and manage? That is for nerds, as much as it pains me to say.
Signal is not "for nerds". The signup-process is not complicated. It's not dead simple, but easy enough. But it's a centralised service, all in the hands of a single entity. Enough said. Migrating to a new device is hell.
It now also has account names, in addition to phone numbers. But please show me where it says you can officially create an account and use it without restriction, while never providing a phone number.
An incredibly simple, one-step signon like here in Arcanechat? It's the kind of stuff that the vast majority of users love. Nothing to think about, nothing to understand, just use.
Secure, as in bot-proof? No idea, probably not.
SimpleX, XMPP, Matrix: The client is more user friendly, less buggy and less "this is for nerds" UI than the clients of those networks, ArcaneChat is more on the WhatsApp-like UI
How on earth do you think the various Matrix clients are "this is for nerds" like and buggy? How do you come to this statement?
Signal is centralized, depends on phone numbers so can't be used by children in the family that don't have access to SIM card yet etc. Registering in Signal is also more complicated, SMS verification, solving captcha etc. No good multi-account and multi-device as ArcaneChat.
Signal can be based on Useraccounts without phone numbers as well.
And the registration process tbh is a pro and non a con - if you don't provide a secured process you will be run over by bots at some time.
ArcaneChat groups are always encrypted and safe against MITM (green checkmark displayed in the group name)
Is that feature audited?
Sorry,but all this sounds more like easy marketing buzzwording and not like actual benefits that have a proven benefit.
BTW: Furthmore your website does not confirm with German legal requirements and makes you an easy target for bad faith lawyers,btw.
The app supports 64bit!! It seems you downloaded the apk for 32bit platform, if you are using IzzyOnDroid repo, that only provides the 32bit apk, switch to the official F-Droid repo, install from Google Play or download the apk for 64bit manually from the github releases page