If something you care about is already performing at industry standard, stop improving it. The real bottleneck is elsewhere, usually something you're bad at or hate doing. Move your energy there or outsource the weak spot.
If the metrics that you have for the thing that you love are above or at your industry benchmark, leave it alone. It's not the thing that's limiting your business because you need to free up all that bandwidth so that you can actually learn the new skills or focus on the thing that really is limiting your business, which is probably the thing you suck at and you don't like doing and you outsource.
