For the front derailleur, I have added an inline barrel adjuster to make it easier.
Front derailleurs do seem to stay stable longer though. The rear derailleur needs adjustment in the first miles of usage as the cable stretches, cogs wear quicker, and the cable needs replacing more frequently.
Incidentally, when I were a lad, having a bike with the old non-indexed system, I can't remember changing anything. That is apart from a gear cable that failed just before the ascent of Pen-y-Pass, when loaded for touring. That might explain the knee pains I had in those days.