I would not want to use fossil at work and I do not know if it could handle projects of that size. Would require manyears of rewriting tools that would not be realistic.
For my hobby projects I have used fossil for several years. It works great and I do not miss anything from git. It's simpler and just nicer to use.
If nothing else I felt like using the same version control system for over 10 years was getting boring. Needed something new to play with. See things from a new perspective. Like playing with a new programming language now and then, even when it is something I do not expect to get much real use out of.
For my hobby projects I have used fossil for several years. It works great and I do not miss anything from git. It's simpler and just nicer to use.
If nothing else I felt like using the same version control system for over 10 years was getting boring. Needed something new to play with. See things from a new perspective. Like playing with a new programming language now and then, even when it is something I do not expect to get much real use out of.