Open-source and proprietary licenses are at two ends of the software development spectrum. The open-source model maximizes ease-of-adoption but doesn't provide much incentive for the developers. Proprietary software provides a lot of incentive but adoption can be slow and burdensome.
Let's assume that a good goal for society is to maximize the rate of innovation in software. To do that, you need a mix of BOTH ease of adoption and suitable development incentives. Source-available licenses are an attempt to accomplish this.
Is this a perfect solution? Probably not. I think better licensing models are still waiting to be discovered.
However, my sense is that these new licenses will accelerate the development of software with limited downside for the user. After all, they are designed only to impact companies attempting to sell a SaaS.
In addition, they have the potential to weaken the tech monopolies which, in my mind, is a Very Good Thing.