Like anything else, you should use it if the situation warrants it.
Do you have issues with dynamic range? I once had a gospel style vocalist with a very big voice and a lot of range - when she hit the loud parts, it pushed the levels to somewhat uncomfortable levels. A bit of compression helped to take the edge off those parts without altering the rest. But if you don't have issues like like that you may not need compression.
Are you going for a specific compressed "sound"? If so then of course it makes sense to use it. Also, if you have issues keeping the vocal above everything else, compression can help keep you at the (high) levels you need without getting too loud. Although if that's the case, you might want to explore ways to get the instruments down, rather than pushing the vocal up.
As for feedback, you still have to be careful. Any make-up gain you use in the compressed channel can potentially push you into feedback territory when there's no signal getting through, even though it may not be there when there's signal present and the compressor is reducing the gain.
In other words, use it if there's something specific you need it to do. Simpler is better.