That sounds very close to my M2. I think it took two months due to the fact I used my MBA for more than 3 or 4 hours a day.
What I don't understand is that I have been using laptops for years. Cheap ones with screen printed keys are the only ones that wore off but I don't remember shiny. Chromebooks that are super cheap to high end Windows laptops for over 30 years. Not a single one ever had shiny keys. Not one.
That is until I got an M series Mac. I don't remember this issue on the butterfly keyboards of the older Intel MacBook Pros. I don't even remember it being an issue on my M1 MBP 13". When I got the true M1 Max 16" MBP was the first time I noticed shiny keys?? Pretty sure.
Up until that point every manufacturer of cheap plastic keyboard keypads on Windows and Apple laptops had keys that wouldn't get shiny.
Then all of a sudden after pretty minimal use of the MacBook you get shiny keys.
It is obviously not a functional issue but it does really look bad on an otherwise spotless laptop.
If MacBooks were cheap or if Apple didn't have such a focus on design and esthetics baked into their product DNA and marketing then I would probably overlook it. When I pay a premium for a product, part of that premium is in the design, look and feel which makes it harder to dismiss.
Having such an eyesore so quickly into the product lifetime is surprising for Apple and cheapens the experience of ownership making one feel the product is not as well made as it could have been.
All of this for a plastic keycap that costs pennies probably. I am pretty sure the genius at Apple could come up with a better material that wouldn't cost too much more and would not wear out so fast. Obviously this is not a huge feat as many other cheaper OEMs manage to use plastics that don't wear down in the same way for many years not months.
Pennies indeed and totally recall we've shared other threads about this issue.
I've not had as much experience, as you likely did with hardware purchase, BUT having used my 2009 (still do) MBP for the last 14 yrs of no shiny keys, then after only 3 months of the M2, having them, it's quite obvious how the material use has been very much cheapened.
I even ordered another bottle of iKlear after seeing this on my M series so soon, and just for the KB really. The new iteration (vs from 2009), I wouldn't use it on the screen nowadays anymore as it seems to smear quite a lot.
My old 2009 matte screen I can still put absolute elbow grease force into it with zero fears of damaging any coating (14 yrs constant cleaning).
For my M2..well...there were pit marks on there after 3 months after much babying really. Due to circumstance of an unfortunate liquid spill, the screen (and everything else) was replaced and there thus far have been no such similar issues. So how do I baby things now? (as I keep my phone or laptop 7 yrs+):
1. Swifer to electrostaticly remove dust.
2. Apple's polishing cloth for KB, trackpad, all aluminium surfaces.
3. Apple's polishing cloth just dedicated to the screen
4. 70% ethanol wipes on screen that Apple's service department here in Germany uses.
5. ShaggyMax KB cover for lid-closed situation (KB marks left imprints on screen).
6. iKlear (unfortunate new formula) for the KB shine
Seems like a lot, quite excessive really but I'm ok with this routine after seeing the physical damage of the screen after hardly even closing the lid 3 months in.