Birds actually have evolved into dinosaurs already.
In reality the birds that are alive today are actually dinosaurs that actually evolved from the large dinosaurs that lived millions of years ago.
Birds, geese, chickens, small birds, pigeons etc are all dinosaurs but just a smaller version of the dinosaurs that lived years ago and were large.
Thankfully today we have no really large dinosaurs walking around today.
A huge dinosaur could easily kill and eat a human and if large dinosaurs were still living today they probably would eat all the humans making the human race extinct.
So while it would be cool to see large dinosaurs alive today it would not be a good thing to have large dinosaurs roaming the earth.