40.1% vs 57.6% is not "much" behind, traditionally AMD failed to get half of that in volume share! 40% despite their extremely aggressive pricing tactics back in those days suggest AMD was starting to make real progress.
Look at the Smartphone market. Apple has ~20% marketshare with 80% or so of revenue. That's much behind.
Law of diminishing returns seems to apply to R&D and company size. AMD is extremely capable considering their miniscule size and relative zero revenue/profits.
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