I feel like a party crasher here... since I don't shoot Canon, but someone asked about the 50mm 1.8 vs the 17-55 f/2.8... I do have a Nikkor nifty-fifty and a Nikkor 17-55 f/2.8 and the 17-55 has made the nifty-fifty almost retire.
It's not about being a party crasher. It's just a different tool for a different person.
A fixed lens is about speed, size, weight and price that a slower, larger, heavier, about 10 times more expensive zoom lens cannot match, albeit being more versatile for certain situations.
You use one for some things and you use the other for some others. They don't need to butt heads.
I'd even say get a manual focus old school one if it will fit on your camera--- oh, I forgot the EOS mount was changed from the old FB Canon mount, so... it'll have to be an autofocus lens with the Canon.
Is that a quip about Canon moving to EF?
It was a somewhat justifiable way to usher their camera system into an all electronic system without carrying the excess baggage that mechanical systems had. Everyone else is actually following suit and doing the same thing Canon is doing now, except Canon did it about 23 years ago.
The EF system is actually able to take Contarex, Contax RTS, Leica R, Nikon F, Olympus OM, Pentax K, M42 and some other lenses with simple adapters that do not hinder image quality in any way. So in essence, any of those "manual focus old school" lenses that you may want to use on your Nikon, you can on a Canon
And it will actually meter on every Canon body, which is something that can't be said on Nikon unless you have a D300 body and above. Talk about Nikon's legendary compatibility.
And for the record, it's FD not FB.