It's really not a "must". Most of time it's a "nice to have", but trust me, lots of people do web dev with single screens and are as/more efficient than you wit

It's really not a "must". Most of time it's a "nice to have", but trust me, lots of people do web dev with single screens and are as/more efficient than you with multiple screens. In fact, your efficiency has nothing to do with how many monitors you have.