A lot of kids ARE reading Conan. It's honestly surprising how many are, because most of RE Howard (and ER Borroughs, and HPL) are on Gutenburg. Got a cellphone? Grab an old book, free and legal. (I'm reading Airlords of the Han, currently.)
Plus, the Schwarzenegger movies, as disonnected from Howard as they are, are still out there, and last time I watched one, it was "free with ads" on youtube; it's now behind the paywall.
In the 2010's, I was teaching elementary; Conan, despite some NSFW/NSFS material, was being read by 2-3 6th graders a year in one school. Mostly on phones.
Also, keep in mind, there's been a continuous coverage of Conan with rulesets for RPGs for the last 20 years... Mongoose, Modiphius, a new one, and the GURPS Conan in PDF. If new blood wasn't finding it, they would not have spent the resources.
As far as modern S&S fiction? I've not read anything newer than about 1990 in the genre. Closest I've gotten is Narnia, Dresden Files, and Percy Jackson.