Definitely others have offered tube/SS hybrids. I know that Luxman had the LV105 tube/SS hybrid integrated amp in the 80s. New York Audio Labs has the Moscode 300 tube/SS hybrid power amp, and I’m pretty sure that Vincent offers one now. I’m sure there are others. It can be excellent if done well.
Many folks are currenlty using a self-selected tube/SS hybrid configuration for bi-amp setups, where a tube amp drives mids and tweeters, and an SS amp drives woofers. I’ve been pretty pleased with that situation.