I think it's in part because of NAT. Less and less people have a real IP address, so they can't share the torrents to others, and most VPNs don't provide an upload port either.

The tracker websites are also increasingly hostile with malicious ads, so those with ineffective ad blockers can't use them.

Good public trackers were shut down. Getting into decent private ones is a huge pain, if you even manage to get an invitation/interview. Some trackers aren't compatible with *Arrs (due to Cloudflare). Seeders and speeds can be awful, and keeping a healthy ration isn't easy for some. If one is willing to pay, Usenet is a great alternative. I run both to cover most ground, but mostly rely on the latter now.

Kids (zoomies and younger) aren't that savvy with computers 

They are much much more likely to use phones/tablets/maybe even Chromebooks. Torrenting is much easier with a PC. Torrent apps for the others do exist, but do require understanding how to use them (and not use them if on cell data without actual unlimited plans). They are used to just streaming things and not really care about keeping the actual files. So even being patient enough to wait for a file to download is at least a good thing I guess.