Its because theres still some big brain work to be done for it. Specifically, once its merged into libsecp, the cryptography software the bitcoin ecosystem largely uses, i think we'll see some more production grade integrations. But still will seem slow comparatively. Software development for tech startups and app is "move fast and break things". We want "move deliberately and methodically and don't lose money" for things like FROS amd other cryptography things. I imagine this may be similar to the nuclear industry in some regards.