Yes ,they are. After reading this article you would agree to what I want to say. What were you imagining that you would manoeuvre through enemy airspace , would trick the enemy SAMs, dodge the enemy fighters and bomb your target??? Very soon we may not need to do this.
Top military nations are in a run to make hypersonic missiles. Hyper sonic weapons can be more survivable because of the extreme speed and altitude. They would be hard to stop. Hard to interpret and even more tedious to engage. Hypersonic means something that can achieve the speeds 5 times that of Sound. So Militaries want missiles and aircraft that can achieve Hypersonic Speeds.
But how they are going to develop such fast missiles or aircraft ?????
There are 2 kinds of approaches to solving the hypersonic challenge. Scramjet and Boost glide.