Not true. Intel has made steady 5-10% IPC improvements from SNB to SKL (I expand on it in fair detail
here and
here, complete with sources!)
You're veteran here and for sure you know what you are saying.
Obviously there were improvement and new instruction sets but they were underwhelming in current applications to say the least.
Of course Intel will still have the performance crown for a long time from now on as they have strong Enthusiast parts, but that is not the mainstream market. The mainstream market is formed by the i3, i5 and i7 non E series.
If anyone, can produce a competitive product here then they are in business, and intel in this area was pretty much sleeping over the years. You said it yourself in those long posts, ivy was die shrink, haswell brought very good power consumption, broadwell its a different beast but I'd exclude as it has expensive edram, and its mostly a very expensive GPU with CPU cores, good for laptops ... but not very viable in my opinion from cost perspective for desktop. Lake mostly die shrink ... again a bit underwhelming.
I found an article which compares different generation performance at same clock also.
It doesn't include the latest architecture though, but it is focused on gaming, which is basically the reason for which most of the people buy these processors, otherwise for browsing or office even the atom is good. If you think is too extreme, fine go with an i3.
See here:
http://wccftech.com/intel-sandy-bridge-ivy-bridge-haswell-graphics-compared-10-difference-average/
I put them in a table also, and compared similar products:
Lowest details i7 2600K @4.5 i7 4770K @4.5 % increase
Crysis 3 91 93 2%
Black Ops 2 355.4 382.8 8%
Bioshock 243.2 265.9 9%
Battlefield 3 199.8 200 0%
Unigine Heaven 4243 4280 1%
Firestrike 7292 7466 2%
Average: 4%
This increase you will probably get by just shrinking the original sandy without any architecture change. Maybe things will change once the new instructions sets will start to be used ... but if they are not supported by most of the computers in use, they will mostly be scattered optimizations in one app or another.
So yes, if anybody can get sandy level performance, good clocks and reasonable power consumption they are back in business.