I agree that a lower-powered scope can be quite accurate on most targets including game, especially when target identification is not an issue. Plinking and even actual competition can be lots of fun with almost no real diminution of performance. Here's an example.
In 1965 at college in Trinidad, I witnessed Pete Grisel win a 400-yd gong shoot against a gaggle of gunsmithing students firing many finely-tuned long-range rifles. His closest competition came from Rick Shay firing a Win 220 Swift with a 10x Weaver and Canjar SST; both of them hit the gong so many times that the watchers all got kinda bored and then Rick missed, or more likely his bullet passed through an existing hole. Pete smacked the gong solidly again with his usual panache and carried home the prize.
Pete was using a 3x Weaver on his elderly and shot-out 243 Rem 722. Point proven. At 400 yards.
However here in MS we've had a Big Bucks Program going for several years now that mandates harvesting only the larger bucks. The requirement is for either 6-point or better, or in some areas 8-point or better, for any legal buck (Eastern count). I quickly found that 5x was simply not enough power to always positively count the number of antler tines in the dark local swampy woods, even with lenses larger and scopes brighter than the older ones. If the deer was out in a fire lane or food plot, fine, but at oh-dark-thirty in the thick stuff I occasionally needed more power and brighter lenses. Prior to this time I had never thought much about the European preference for large scopes but now it was easy to see how something like an 8x56 would be a big help when trying to see into the darker areas of the deep woods. Just a thought.
Regards, Joe