I think this is an overstatement. I've put about 16 hours into Silksong so far, I've pretty much completed around 8-10 zones or so, unlocked most of the abilities and stuff.
I don't think Silksong is that much more difficult than HK. Honestly it's been so long since I played HK that I'm not even sure it's more difficult at all but it probably is. If you went to Hunter's March as soon as you found it you probably had a bad time but going in there later on was honestly pretty easy. And aside from that and maybe a couple other spots it's been fairly alright in terms of difficulty IMO.
Everything so far has felt achievable and reasonable to me, having played HK, Dark Souls, Elden Ring and other similar games I don't think Silksong is significantly more difficult than any of those - yet.
Maybe it gets crazy later on, but that wasn't the claim in the article. The article claims you can hardly access anything without extreme effort and I don't think that's true at all.