It's not a change that happened in the industry, it's just about who is responding in this thread. The people you see talking about bids are likely either:
#1: Running under their own authority, and are both the driver and the dispatcher for their own company.
-or-
#2: Working with an extremely rare small carrier that allows the driver to help bid their own loads.
I did the latter for 2 companies that have asked to remain unidentified, one of which I helped get their authority set up. So basically, most people talking about bidding are owners, or very close with the owners of the carriers, I suspect.
Most carriers won't allow drivers to bid loads for many reasons, but chiefly because they don't want the drivers to know exactly how much they're being paid on the loads, in my opinion. That reason might not be primary for ALL carriers. I'm not trying to make them all look bad or throw anyone under the bus. The truth of the matter is, it takes more money to run a business than a lot of people think, and if people saw what they made, most people would have a negative kneejerk reaction that simply isn't worth the hassle for a larger company that has to keep up morale on a macro scale.
That said, the type of dishonesty required to maintain that facade, and avoid said hassle is distasteful to me, and so I will sadly be unlikely to get rich running my own carrier any time soon. But I -might- be able to make a comfortable living doing it. Time will tell.