I think you'll find that everyone has already left them. It's hard to see what PB will actually do now as so many already use free or low cost cloud storage and there are many others who still permit links etc. Some weeks ago I just logged in and deleted absolutely everything.
Either a) all the people who were using Photobucket to host content that they had monetised will pay up and Photobucket will survive or, b) They'll disappear like a million other websites before them
This was their last gasp effort to save a doomed business model.
The only 'free' storage that will remain, ultimately, is the 'free' storage you pay for in some other way - Google (paid for by all the data mining they can monetise off the back of your data), Amazon (paid for by Prime subs) etc etc.
Trust me, imgbb.com, postimages.org etc will either stop 3rd party linking or disappear, eventually, because 3rd party linking destroys ad revenue.
Pretty much bang on. Most consumers seem to think everything on the Internet can be provided for free, but in reality, providing internet services is incredibly expensive, be that email mailboxes, web sites or cloud type file hosting. A 500Tb all flash array will easily bust $1m, and have a life of 5-7 years. Then you need all your front end servers. And network kit and load balancers. And bandwidth/transit/peering costs.
If ad revenue is not coming in fast enough, a free service can only last until the investers' money runs out.