If you answer in the language you know best, it'll be easier to others to understand or translate, especially if it's English.
You could translate your message to match the language of the comment, but if you don't know the language, how can you know if it conveys your message correctly?
Overall, I'd say it depends on the specific community. If you try to inject yourself into a conversation in a Japanese language community, it may indeed come off as rude or ignorant.
The best solution may be to post in both languages?
It's like saying list.isEmpty() over list.getLength() == 0 is a picky optimisation.
There's a developer out there who coded this and they obviously don't know what they're doing. One day they're gonna iterate all rows in the database to check if it's empty. You have to flag these issues early and teach the newbies.
The thing about email is that the software is proprietary. Each of these providers has their own implementation of the interface, features, and integration with their tools (Google drive, photos, etc).
As long as lemmy servers run lemmy software, this won't happen, or at least won't be an issue as you can move to another server and not have to change your usage habits.
However if some server owners decide to fork Lemmy and develop their proprietary server, overhaul the UI, add features and attract users, it will start to become a problem.
Notably, roomba vacuum cleaners use cameras instead of lidar that other robot vacuums use. I bought a high end roomba a couple months ago and it was crap at navigating my home, while my old xiaomi with a lidar works perfectly fine. Needless to say i returned the roomba.
I have a baby. No need for an alarm, he has one built in 👍