It's a combination of development in CPU performance. The peak performance levels of the Apple's ARM architectures have reached peak Intel/AMD levels around the

It's a combination of development in CPU performance. The peak performance levels of the Apple's ARM architectures have reached peak Intel/AMD levels around the Apple A12, so they haven't been at this level for that long. In addition, Intel has not been good at iterating on their hardware since Skylake in 2015 and don't look to be making great strides in the short term. It's like the PowerPC->Intel story all over again. Intel was not at PowerPC levels that long before 2005 (PowerPC had substantial advantages from 1994 to 2002), and IBM was not showing evidence of improving the situation beyond 2005. I think before 2018 it was unclear whether an ARM Mac would be superior in terms of performance/heat/power, but I think given Intel's lull and Apple's continued improvements I think the best decision is clear [if you think it is worth the transition, which is the most debatable item].