Harmony OS is a general purpose OS, I doubt that if I was trying to get the server version of it working that the finer points of the settings would be documented in English. On-going development might not be in English.
The commands used in programming languages are in English. 'strpos' might not be an English Word but it is still English. There isn't a Spanish/Russian/French or other language version of 'strpos'. Same with HTML. 'body' is always 'body' whatever the language the content of the page is.
I don't get your point.
Taken as absolute this is untrue:
The thing is entirely in French (SI ALORS SINON, POUR TOUT, TANT QUE...) with English later tacked on, and a technical crapfest (I'd rather code in INTERCAL), but it does exist and is widely used around here (and by my own admission, produces working - if buggy - software that solves real life problems for people).
Combined with OS, software, and resources (http://sdz.tdct.org) set to French all around, a lot of the French dev community lives in a secluded language bubble entirely outside the thriving world you and I experience. Even if using non-French keywords, they could just as well be replaced with 'qux', 'frobnicate', or ':roller_coaster:'. To most of them, they're just tokens learned by rote. The overall quality of this community is terrible. At some point some contractor of a customer was hell-bent on explaining me that HTTP redirections were happening server-side (through pixie dust), therefore it was safe to place plaintext auth credentials in the query string.
This creates a conundrum: any English content you poke at them is met with great pushback and distrust (mostly from fear of judgement and fear of the unknown), while the typical English-speaking developer will feed from English resources and produce in English resources. This in turn means that practically no French resource is produced (actually untrue, there has been and still is, but they lag behind a lot and usually don't survive long), further widening the gap.
PS: I may sound adversarial but that's really not the case, it's more than I'm appalled. I tried to break the bubble by producing some French content and help people but the pushback, inertia, and status-quo is incredibly powerful.