The average programmer skills probably stay constant but the average line of code is dependent on how many programs have versus how many lines of code they accu

The average programmer skills probably stay constant but the average line of code is dependent on how many programs have versus how many lines of code they accumulated so far. However, you can bet older products will have more features by the virtue of code accumulation. With carelessness of some programming team, they become slower. Others, being more careful, will remain the same. Still others, gain in performance with practices that allow them reliable improvement in code quality. Programs might have done more stuff, or not depending on what software you're looking at. Browsers on the whole do more stuff, but they also do it fast and efficient. The evolution of software is much more dynamic and tricky to figure out. They are like corporations. Some corporation accumulate bureaucracy, others remain so-so, and others shed accuracy as a matter of survival.