While I won't argue about the "(going) larger rear sprocket is better (for the components life time span) than smaller front sprocket" theory, I think it is one of these stories that are overly enhanced story carried from old days. (Just like the story of "mold release on tires makes brand new tires slippery", I've been hearing those stories from early 80s over and over again.)
#1When people discuss on the subject like this on the internet forum, people tend to focus on the negative effect (chain extra wear)
WAY more than it actually matters in the real life.
The simple fact is, countershaft sprocket size
IS a factor in chain life (wear), but
it is NOT a dominant factor, AT ALL.
Riding environment and maintenance play MUCH, MUCH bigger rolls.
#2Motorcycles are meant to be ridden. If you are relatively new to riding a motorcycle, or new to particular type of motorcycle, and willing to try lowering the final drive ratio, then, try a -1 tooth counter shaft sprocket, and don't worry about what nay sayers say.
It's a whole lot of cheaper, easier to do.
Or, you can wait until you wear out your existing components, save up enough to change the entire drive components, keep riding with too tall gearing and suffer, while you could have enjoyed the ride with slightly lowered final drive.
If you are new rider, and short and light weight, you might stall and drop your bike, while that could have been avoided by lowering the final, by simply changing a countershaft sprocket.
#3The above story comes from the experience, NOT from the "theory" talk on the internet.
Back in 1983, my motorcycle was this
1982 Honda XL125R, with whopping 12HP (at the crank ...)
I swapped the front sprocket from 13T to 12T.
Partly because I wanted slightly lowered gearing for technical trail and such, but
I mostly wanted to lower the final because I wanted to pull wheelie !
(And I couldn't afford to buy a new chain and F/R sprocket set.)
I rode this bike every day, every night, and I rode it everywhere. Rain, shine, mud, sand, ...
I never experienced any negative effect with -1 tooth front sprocket.
Same story with 1990 KDX200
I went to 12teeth (stock was 13 teeth) front sprocket.
I ride this much harder than XL.
Never had a problem.
Sometimes, people just repeat what they have read somewhere on the net, not talking from their own experience.