Giving up model selection is giving up some level of control and understanding.
I have no doubts over the long haul what is being said here is true, but I'm confident the tooling to perform model selection will be pushed upstream, not downstream. Model vendors have a strong incentive to produce controllable results and will follow their own benchmarks.
The entire "self-improving" concept is reliant on getting better at getting to a solid result with the right efforts and subagents.