Safari and Edge (
which is also Chrome) having twice the dismal market share of Firefox doesn't make the browser market competitive. Safari is an appliance delivered exclusively on machines manufactured by a single company that holds a small, though luxury, part of the market. Edge (
is Chrome, and) is only available on one OS [edit: I'm guess I'm wrong about this, didn't imagine that Edge would be available on Macs.]
Firefox is the only "credible" competitor, although Firefox's only profitable customer is Google itself.