Not really. If you compare it to gaming rigs, they bear radically different architectures, so you can't really compare them by TDP or power requirements. They don't emit the same hear or require the same amount of power per TFLOP. And I wouldn't be surprised if tflops also wouldn't translate to actual compute room for shaders.
Even if they did, 100w should be room enough to play relatively recent titles, specially indie ones. Nothing really excuses Apple from this contempt it has for the gaming market.
I briefly owned a Steam Deck (before returning it), and it seems like most users tone down their expectations a lot compared to PC gaming. 30fps at the Deck’s low resolution seems to be the norm for recent games. Enough power to have fun, sure, but I think people would rightfully pan it if it weren’t Valve.
Expectations are lowered appropriately, I think. There are a number of other handhelds on the market. Of the high end PC handhelds that came out reasonably close to the Steam Deck, they have to trade away a lot of battery life to perform better than the Steam Deck. Valve was clearly optimizing for battery life and I don't think it was a bad choice. The Switch 2 isn't even held back by x86 and it's battery life is still quite painful.
Now, handhelds with newer hardware are definitely going to trounce the steam deck without having to trade away battery life, but I think they did the best they could at the price point and time.
The battery life is nice, but the Steam Deck is huge - big enough that I'd feel incredibly silly pulling one out of my bag on the train - so it's the least I'd expect.
Even if they did, 100w should be room enough to play relatively recent titles, specially indie ones. Nothing really excuses Apple from this contempt it has for the gaming market.