Only if you leave them enough of an ecosystem to do so. That's probably the most important part of "taking care of nature", and one we're currently failing at terribly.

True, we should let them search for food, especially when there's enough food around.

When food is scarce (winter) it may be a different story, though. And water fountains in the summer are good not only for the birds, but for other wildlife as well.

What if I limit your food source and make you leave your house / apartment? There's a chance you would need some assistance.

The US has lost about 25% of its birds in the last 50 years

we’ve destroyed much of their habitats