Like Rico says, scoring is always relative, but that relativity relationship is constantly changing with each new advent in the bowling world.
Back when rubber balls were still being used a lot, I was learning. When polyester was king, I was considered very good. I had a hard time making the adjustment to urethane (because it hooked so much more) but finally did, and have never been able to fully make enough changes in MY game to be able to utilize the full potential of the resin ball era.
While averages, and scores, have skyrocketed around me, I am still at about the same average level I was at 25 years ago. Scoring is relative to ones ability to utilize the environment you compete in.
I was able to manipulate the scoring environment I came up in very well, but cannot do that at the same level with the environment today. Slower speed, early roll release, and hitting the ball on the upstroke was very natural for me, so the game was actually easier for me BEFORE all the technological changes. My game was based on an entirely different set of parameters than those conducive to today's environment, and it shows.
Back then, I was a power to be reckoned with. Everything it took to score well, I did naturally. Today, a lot of what comes naturally to me is counter productive to scoring, so knowledge has helped keep me in the game, but all the "improvements" have done little or nothing for me.
Scoring is all relative to the baseline. When the baseline changes, so do the people who are able to best manipulate the "new" parameters.