Having chickens around is my favorite part of having chickens. I have problems with anxiety and depression, and watching the chickens peck around in the grass relaxes me a lot. It also helps that I have a few in my flock that like to cuddle me, and they all come running when they hear the sound of my voice.
The eggs are a bonus at this point, even though that's why we originally got them. I think if nothing else I will always have a flock of chickens now for therapeutic purposes. We also use photos of the chickens on merchandise that I sell online, and I am saving up naturally-shed feathers to use in jewelry making (once they've been sanitized, of course.) I eventually want to get a flock of meat birds, but that will have to wait until we have a second coop and run to keep them in.
I got them because I had a vision of myself gathering a beautiful basket of eggs. I will get more because different breeds will give me a bigger variety of eggs. But I enjoy watching them and listening to them and talking to them and discovering new little chicken mysteries every day and learning how to treat them well even more than I enjoy gathering and arranging the eggs. I hope I can always have a largish flock of chickens.
We have a few turkeys right now that will be extremely difficult to part with because they are so much fun. We are talking about doing meat birds ... if we can figure out a way to be less personally attached to each and every one.
If you get meat birds, get chickens that all pretty much look alike. If you can't tell them apart, you are less likely to see individual personalities and quirks that will make you attached to them. By that same token, don't name them. Very few people can bring themselves to eat something they've named. Take care of them--feed them, water them, clean their coop and run, and handle them enough that they are reasonably tame, but don't cuddle and play with and baby them like you would your other chickens. If after you do all this, you still have a chicken or two that stands apart from the crowd, don't feel like a failure if you decide to keep it aside as a part of your permanent flock (Assuming it's a variety that can thrive--some varieties bred for meat don't live long regardless of what you do).
I've never raised meat birds before, but I have a lot of experience with avoiding attachment to animals if I know they're not going to be in my life for very long. It's a tricky art to care for an animal, give it all the love and care it needs to thrive, and do so without becoming emotionally attached to it.