Light with 2 4-way switches and 1 3-way switch
A 4 way can be used as a 3 way, you just have to connect travelers to common colored screws, and attach the common wire (the hot or switch leg) to one of the other screws leaving its matching screw empty.
But seeing all terminals have wires this does seem unlikely. It would mean a fourth wire is uselessly connected to the switch and goes to the light unused or that it was routed to another junction box where another switch was intended but not installed.
You could test by removing one wire at a time from 4 ways looking for the wire that has no effect. Permanently insulate that wire and connect the wire it travels with to the common on the new 3-way. (If you do later find a mystery hidden three way it will act like a kill switch, only allowing the other switches to function when it is in the closed position.)