I've noticed the exact same thing today. I was starting to think I unwittingly did something terrible to turn all the clients against me. Perhaps the American elections and the other political and economic issues around the world are impacting on business more than we realize.
Also, many smaller businesses have closed down or have been absorbed by larger corporations. Statistics have shown that most small businesses close their doors in the first five years. Those of us who have been around longer are privileged.
Why people post jobs without any inclination to hire, is beyond me. Perhaps they are trying to figure out what the project will cost them, and when it's above their imagined budgets, they simply abandon it.