It mostly comes down to manufacturing processes. When you compare 5nm Apple hardware to 5nm hardware from other competitors, the power/performance disparity closes significantly. Since Apple is the biggest though, they can out-spend anyone else who tries to buy out the latest node right now. This has been the case since 2020, and seems to still hold true.
Design makes a big difference, but Apple is not the only company designing high-performance ARM cores on TSMC's finest. Some might even say they aren't the best designers doing it, either.
