I'd vote for more Pcores and no ecores. That would have been better in every possible way. Downside for some people would have been less cores in gerneral for sure.
Then Intel should only use those since these are so much better.
Haven't we been on this merry-go-round before?
E-cores make sense in multi-threaded loads.
Ideally, processor should be made just with P-cores and enough thermal and power headroom it could all run with full frequency.
But they don't build processors like that for a long time now. Because they can't - there is too much difference between workloads that require a few cores running as high as they can (games, non-multi-threaded applications) and true multi-threaded workloads.
So at first we got CPUs that can boost any core to boost clock - but with additional loaded cores that clock got lowered, so the CPU remained inside power and thermal limits.
Then we got CPUs that had preferred cores thst can boost highest, and other cores that can never achieve the top frequency, but are otherwise good enough when they are loaded as additional cores in multi-threaded workload. Intel had that before, Ryzen has that inside single CCD, and with two CCDs one is faster - capable of reaching full boost clock with low threaded load, the other is not.
Intel has now pushed this step forward with big-little design, with P cores and E cores.
Most of the downsides now lie squarely on Windows scheduler, and software not written with faster and slower cores in mind - but that also punishes performance on previous Intel CPUs and all Ryzens - if it can't properly distribute loads between P and E cores, it also can't pick fastest cores in CPUs where not all cores are equal (all CPUs for quite some years now).
But that is the future, and AMD will also jump on the bandwagon. Because it makes sense.