[EnderMB]

I think the gig economy has helped #1 considerably.

In the UK, at least, a lot of developers reach a point where their pay is limited to what a company is willing to pay them for a full-time role. When you get to this point, you have a choice: stick to the full-time market, or go into contracting. From a money and freedom perspective, it's almost a no-brainer. A competent senior developer might make £45-50k, whereas a contractor will earn considerably more if they find consistent work. If they're not lucky enough to find back-to-back contracts they get a lot of extra free time to build their skills even further, or to diversify their offering.