Delta chat is basically email.
and how is that exactly a problem? the protocol is email, but email done right is actually good and fast, as it can be tested if you actually try out the app. The new chatmail servers are optimized for chatting, the main reason classic email providers suck is because they have to deal with spam and arbitrary decisions like gray-listing etc
without being picky about quality of translations vs Google Translator, this can’t be used offline in the phone/android, right? maybe trying to setup the server side inside Termux could work, this doesn’t solve the problem of translating text just by pointing the camera to some banner or traffic sign etc. which is useful while traveling in a foreign country etc.
Can DeepL be used offline? One of the killer features of Google Translate IMHO is the ability to download the language models and translate offline, that plus the integration with Google Lens which also can be used completely offline to translate text in real life pointing the camera or from an image is a killer feature I have not seen other alternative provide, I would like to be completely independent from an online service, even if it is Google if you download the languages and block internet access of the app with a firewall that is better than an online service.
I am currently not using Google Translator, uninstalled the app together with Lens and have a degoogled phone now but I am suffering in silence every day
https://arcanechat.me/ is also European (Germany) and is decentralized, fully OpenSource, free/gratis and registration requires ZERO personal data! Everything is End-to-end encrypted between people, server can’t see any data which is encrypted and stored only temporarily on the server
you should try it again, Delta Chat is totally on a different level than a few years ago, there has been tons of improvements, I started using it around 2018, now I am even contributing to it