I've tried Topaz. I'm just fascinated with AI and the possibilities in upscaling/interpolation, but yeah I kind of agree its not really ready for anything except playing around. Lots of people love to play around though. My most successful attempts have been 1080p input sources that are excellent quality already (crisp, good bitrate, bright) upscaled 2x to 4K with Gaia, the result look quite decent and very little artifacts with what to me looks like a tiny bit of grain by default. Interpolation of 30fps sources are 'ok' with the heaviest model, but it really needs 60 input to scale really good IMO. Less than 30 does not look good, but I bet AI that understands context could improve this in the future.