So we've hit a wall in trying to understand how dark energy works or how its parameters arise. But I don't think it's logical or helpful to conclude that an anthropic explanation is the only option we have left. Maybe we just haven't yet figured out the right questions to ask, that might open up a new field of investigation that could lead to new physics that provides a mechanism for how it works.
For example, we also still don't understand the nature of dark matter. Even more fundamentally, we still don't have a solid understanding of time, and why there is an apparent flow of time in one direction from the past to the future, or whether spacetime curvature induces quantum state collapse, or how the universe began with such low initial entropy.
Maybe discovering a deeper understanding of the foundations of the physics we're already familiar with will open a way forward with understanding how dark energy works.
Yes, there is basically no real evidence for any of the multiverse hypothesis. If they're right then physics and cosmology has nearly ended in its reach of what is knowable. It feels so much like this is premature surrender and physicists are turning themselves into religious philosophers just because they can't think of anything better. If we had been backed into this wall for hundreds of years with nothing better, then I might agree that the program was over, but I think the whole anthropic/multiverse idea is a condemnation of how sold physicists and cosmologists have gotten on one possible solution, and indicative of the fossilization of some of their ideas. We need a new Einstein to do away with the modern-day aethers...
For example, we also still don't understand the nature of dark matter. Even more fundamentally, we still don't have a solid understanding of time, and why there is an apparent flow of time in one direction from the past to the future, or whether spacetime curvature induces quantum state collapse, or how the universe began with such low initial entropy.
Maybe discovering a deeper understanding of the foundations of the physics we're already familiar with will open a way forward with understanding how dark energy works.