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There's no getting around that x86 is showing its age architecturally. Even discounting all the ancient backward compatibility, like "real mode", it's getting awkward.

The Intel x86 CPU's will never be able to match the performance of Apple M series CPU because of a design problem with the instruction set. When x86 was designed parallelism was not an issue because instructions were decoded serially. Today CPU's gain most of their performance from parallel decode. The ARM instruction set is mostly fixed width while x86 is variable width. You can't decode instructions efficiently in parallel when you can't easily determine how to break them up into separate instructions. For example x86 gets a sequence of bytes and first needs to decode the bytes to figure out how to group them together into instructions. ARM can skip this step because the instructions are simpler and fixed width. In that case it can easily issue groups of bytes to parallel decoders. Here is an analogy: Imagine someone trying to direct groups of people to into separate at an airport security screening. They need to make sure that families go together in the same line. If each family could have 1-4 people then they would need to ask each person which family they belong to (i.e. x86). If there is a requirement that all families have 4 people then they can all move through to the x-rays without being asked.