Gamechanger and iScore track strike % so you can get a lot of data from these apps. At the rec league level I have seen that the teams that can get most of their pitchers throwing above 50% are doing pretty well. The best pitchers in rec ball are two types:
1) high velocity (so long as they can throw at least 50% strikes)
2) good command and possibly change of speed (to be used only against the better batters) - but this requires at least 60% strike percentage, and preferably 65%.
Once you get into travel ball, you generally won't even get to pitch if your strike % is below 50%, from what I've seen. Command - the ability to throw pitches to certain location (low/outside corner, high/inside corner, etc.) becomes a very important tool to make life difficult for batters. Those players who have the ability to throw a strike at will (above 65%) can now focus more on locating pitches precisely and that will result in more balls.
If you have an 80% strike %, it likely means you're not aiming for the corners of the plate, which you should be doing any time you have a favorable count against a good batter.
Generally a good game plan is to just throw strikes down the middle against lesser hitters but if you know a hitter can easily get quality contact off of fastballs down the middle, you're better off going for corners and changing speed to keep them off balance, which increases the chance they'll get a low quality hit like a popup or weak grounder. Throwing these kinds of pitches will cause your strike % to go down.
I had a kid on my team last year with a 75% strike % who kept throwing pitches right down the middle and the opposing hitters kept hitting him, for a collective batting average of over .400. This was rec ball so that is a ridiculously high batting average against. Towards the end of the season I finally got him to start hitting corners of the strike zone. His strike % went down a little but the opposing batting average went down a lot.