It's not unheard of, but you have to be a little crazy to do this in 2026. I developed Chrysalis entirely in C (with GLFW3 and FMOD for audio): https://store.steampowered.com/app/1594210/Chrysalis/
what am i up to with it? creating hardened vanilla base servers (no mods) and ensuring it gets compiled in a way that doesnt impact lightsaber combat. everyone has failed to do this for 22+ years because there's lots of subfactions in this game who fail to prioritize this as they have other priorities. tons of people who enjoy the prospect of modding the game or making it something different but the tiny remaining competitive player base has only ever needed the base game and what shipped by ravensoft in 2003. generally the guys who are competitive players arent.. coders. the game is ultra sensitive to mathematical FPU differences and virtually all recompiles of the game in the past decades completely failed to guard this, so every game mod and attempt at creating something better hasn't stuck for competitive players _except_ for something called ybeproxy which was an attempt to hook the original game engine binary and add some security/anticheat layer.. this was the best attempt to date but it still negatively impacts the fragile lightsaber mechanics.
I love seeing people try to revive old games and improve them for players. I've made a couple of contributions to VCMI, an open source implementation of heroes of might and magic 3 that I used to play as a kid and it's so rewarding seeing people use those.