You're right, performance has improved, but market positioning vs its nearest competitors really hasn't. Below I have the September 2022 review and the October 2023 review.
A750 (using the stock intel version for consistency) started 16% behind the 6600XT and 4% behind the 3060 12Gb.
Today, the A750 is 8% behind the 6600XT and 2% behind the 3060 12GB (and back to being 16% behind the 7600).
The mix of games have changed somewhat to better favor the A750 in the newer October 2023 review (including Resident Evil 4 and The Last of Us which as mentioned had huge performance upgrades) but the actual market positioning of the A750 hasn't really changed in the grand scheme of things.
I agree that there are circumstances and reasons why I would buy an ARC card (I've been personally tempted from the tweaking and testing standpoint alone, much like DaPunisher) but I would still be hesitant to recommend it over equivalently priced alternatives from AMD/NV at this time.
Review from September 2022:
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Review from October 2023:
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