Usually bunion removal surgery is done at the same time as fusion (I've had both big toes fused and bunions removed at the same time.)

Joint replacement in the big toe is usually not recommended over fusion. In most cases, there isn't much mobility loss with fusion anyway. I haven't noticed. Running is most likely not possible or recommended after fusion, I think.

Joint replacement in the big toes have a high rate of failure, although you can verify.