Many games will run on 16GB RAM + APU, but to give a real world example - when I played around with an APU on 16GB RAM, I found various Indies like Quern Undying Thoughts, The Forgotten City, etc, crashed at 1080p (uses 6GB VRAM + 5-7GB RAM as the game goes on + 2-3GB W11 = you're right on the limit of 16GB even without anything running in the background). Even games that were 2-3GB under the limit noticeably stuttered more + had longer level load times when revisiting areas, etc, vs 32GB RAM due to Windows File Cache having almost no space to cache the frequently accessed game files, so more data has to be constantly re-read from disc instead of RAM. I'm definitely not one of those people here who buys a 16GB VRAM GPU then immediately starts strutting around with "OMG, 8GB GPU's are completely worthless for gaming", but there are absolutely Indie games that use 5-6GB VRAM (and almost as much RAM for the game) even at 1080p, without even looking at AAA's. Windows 11 and whatever client (Steam, Galaxy, Playnite, etc) you're using all throw another 3-4GB weight on top of that. DRAMless NVMe? Another +100MB for HMB, etc. It all adds up.Personally, I don't think RAM capacity is an issue. Battery life is. If I could get 2-3 hours on full blast in the latest AAA games at high graphics, I'd see some merit in the low RAM argument.
And if you put Windows at fault, just get a Steam Deck - it's cheaper, and you'd have to limit the Zotac Zone's power consumption to Steam Deck levels to get a decent battery life anyway.
I agree with you that they're at their best for lightweight games due to battery life, but I think the complaint many have is the specs in relation to the price / restrictions. If I were buying a handheld with 16GB RAM tomorrow and had to limit choice of gaming to only lightweight stuff, then I'd probably go for a £350-£480 Steam Deck. As soon as you drift into £800-£850 pricing territory though, that's only just short of a Black Friday gaming laptop deal, or the £950 I'd rather spend on a MinisForum v3, same 8840U, double RAM, double SSD, and 14" vs 7" is a whole lot more pleasant for web browsing / office / watching Netflix in bed, etc, outside of gaming, but still "hand-holdable" with a lot less bulk than a normal laptop. Seems to be "nice idea but that pricing is stuck between a rock and hard place".