Demos outside of small sized intros usually still work with traditional mesh geometry, so RTX could have been helpful at least there. It's just not that many people are doing big demos anymore.
For small intros it's almost as you say -- RTX is mostly uninsteresting and not that helpful for current status quo at least on the surface. However, while SDFs are do indeed provide a relatively cheap and intuitive way to specify your scene spatially to allow ray tracing and GI approximation with varying degrees of fakiness, they confine you to a rather limited abstract geometry stlye. Anything beyond yet another repeated-rotated-cube-with-cutouts-fractaled-to-death is rather uncomfortable to pull off and is also usually very slow (see iq's incredibly realistic works). That's why most of the intros from last 10+ years look rather similar.
Also, I've been recently playing with Vulkan ray tracing extensions and turns out it's not that hard to pull off. There's a considerable upfront cost (Vulkan being verbose as it is), but it's totally manageable, around maybe 10-20k compressed. The entire PoC intro with music was about 60k, and I haven't even started optimizing it for size. It had also been compressed with "just" UPX (apparently ray tracing extensions work only in 64-bit mode, so more sophisticated compressors are out of the question). I've heard that recent work on native 64bit compressor from Ferris removed another 16k from it, so there's definitely a lot of room for actual content in 64k+rtx.