One could argue that Lunar Lake is exactly that. At least, it and arguably AMDs monolithic mobile SOCs starting with Zen 2 have shown that one can be competitive in terms of efficiency with ARM equivalents. The 4800U and M2 were more closely matched than I feel many in the media gave them credit for.

Lunar Lake now appears more than competitive in that regard with even the higher end M3 SKUs, though of course M4 Pro and Max are around the corner. Apple, more than the ARM ISA, seems responisble for the prevailing impression that ARM is inherently more efficient because Apple were simply the first to put such major investment into targeting specifically mobile SKUs, rather than scaling down from server focused products. Snapdragon X showcases that quite impressively, ARM based but efficiency wise Apple, Intel and AMD SKUs appear more competitive.