Just like all bikes, HTs have come a long ways in capabilities over the years. IMO, most of the improvements in bike design have come from relatively simple geometry and wheel size changes. I had a Sir9 rigid until the frame broke years ago. Lots of fun and great to mash up certain climbs. My subsequent Stache was far more capable. A bit unfair as that bike has giant 29+ tires and the added front suspension. DH times not far off my 120 FS (granted, which is more to the poppy XC side than the trail side of things).
Problem is when you start pushing a HT and start making some mistakes, you really feel them. Drops over 6" just aren't fun (I know, BMX guys jump off of roofs, yada yada). Hit a square edge at speed and it feels like the rear triangle is about to rip off.
Let's just say 95% of my riding is on the FS. It does everything better at a mere 3x the cost.