Ki, Qi and Chi are not the same word by that logic, sorry. It's exactly the same situation that you're complaining about - Qi and Ki are anglicizations of the Chinese and Japanese words respectively, which are similar words which describe essentially but not exactly the same force. Chi is dubious anglicization of one of them, I presume Qi.
You can't have it both ways. If you'd gone with Qi and Chi and not thrown Ki in there to ruin your point it would have worked though.
Alright take Ki out then. Shows how well I know my Chinese from Japanese
Ki and Qi are in fact the same concept and same force, just Anglicised differently and from different languages. Chi is the Wade-Gilson translation of Qi, from which we also had Canton instead of Guangzhou, and Peking instead of Beijing. Ki is the Romaji or Latin-letter form of the Japanese word, which was a loan from Chinese (as are MANY words in the Japanese lexicon, despite unrelated language families).
- 氣 is the traditional Chinese character, Korean hanja, and Japanese kyūjitai ("old character form") kanji. This is read as Qi or Chi by translators to English from Chinese, and as Ki by translators from Japanese.
- 気 is the Japanese shinjitai ("new character form") kanji (created so that writing and printing could be made quicker and easier).
- 气 is the simplified Chinese character (same reason as the Japanese shinjitai, different country).
Obviously different cultural traditions will influence the development of the philosophy, but the Japanese and Chinese philosophers and martial artists would see these as fundamentally the same concept, though spoken of differently depending on the tradition they're trained in. Qigong practitioners don't speak of it the same way Aikido practictioners do. But Chinese, Japanese, Korean, Vietnamese martial artists all are using the same term at times, and they're speaking to the same force of energy, just in different cultural and traditional interpretations, passed down over the centuries.
D&D probably should have used the word Qi, but Ki is a sacred cow of the game, and Monk players would probably get confused if it changes. Just as real world Paladins were knights of Charlemagne's court, not generic holy knights bound by a specific type of oath, and real world Druids were the scholarly and priestly caste of Iron Age Celtic societies across Europe, not nature-wizards who can turn into animals. The narratives are related, but D&D is drawing on specific myths (such as the Druidess that helped Lugh's father and mother meet). With Monks, they're most specifically drawing on Shaolin martial arts traditions, but also on Japanese aikido and jujutsu and judo (and now kendo and aikiken with the kensei).
As for what this means for D&D?
Drow and Duergar are not literally the same word. Drow comes from the Scots Trow, Drow, Trowe, or Dtrow, which is actually from Norse Draugr (of Skyrim fame) meaning revenant. There is some folk etymology working though in Scotland that tied Trow to Troll as an alternative. That said, Duergar and Svartalfar both mean the same thing in – Dark Elf and Dwarf. The D&D Drow is a derivative by name from Draugr but by description from Svartalfar.
But D&D has sacred cows, and Dark Elves have been developed as separate from Dwarves for many decades in fiction, now. Same thing with Genie and Djinni. And Gorgon and Medusa. They all bother me when they're used to mean separate things, but the fictional history has changes things.
I think I'm most bothered by Genie and Djinni, though, because those are literally pronounced the same way. Maybe D&D designers pronounced Djinni as like "Jin-knee" rather than Jeanie, though? Seems pretty weird. I'm not sure there's a better encompassing term for them though. And Dao and Marids are completely unrelated in mythology (if anything served the Dao roll in Arabic tales, it's the Ghouls), but oh well. In Albanian lore, Xhindi (from Djinni) are aetherial Elves. We treat these things like they're so different and unrelated from each other, but it's all a spectrum and reinterpretation of tales as befits a culture's ideas.
