i think depends on your social group

like the one u mention "sesama rakan", bagi rakan sekerja utk komunikasi melalui online, ada social group yg pakai BM, ada yg pakai English, tak semestinya English, really depends on your social group

kalo utk Netflix tu, mungkin kebanyakannya semua filem Netflix tuh filem English, so I assuming most of their viewers/customers faham English kut, tu sebab dia pakai English...

kalo rakan awak semua paham BM & tak berapa faham English, masa tulah social group tu pakai BM

tu kena tanya awak sendiri nape

mungkin sebab
- you assume everyone in your social group paham English
- because you want to standardise in one language so that your other coworkers can also understand, just incase email needed to be forwarded to boss or other coworkers or even clients
- avoiding miscommunications, company's documents, instructions, manuals, etc are in English, easier to communicate in English, again depends your social group
- lain la cerita kalo keja kat gomen, mostly are in BM oredi, even email & company's documents.

again depends your social group