It literally does he wants a one off purchase, i.e. stand alone. Google docs is not that, its a way to make sure google retains all your data under the banner of free lol.
I happily pay for 365 at 7 quid a month for 5 family members, who each can have it on 5 devices, each with a TB of online storage, I think along with Microsoft Xboc Pass, is amongst the best value subs out there. Sure if I could purchase office 365 for say a hundy I would but thats not an option and never was.
I notice that office 2021 keys are available on various websites for a few quid, this is relatively risk free if windows 10 is anything to go by.
Otherwise its 250 squid.