> a need for degrees as a signal for baseline competence/barrier to entry
The signal is valuable. The unnatural barrier to entry is, at best, unethical.
Ideally, the barrier to the opportunity to earn the credential would not exist. It should be available to everyone worldwide.
Individual research positions should be applied for. Certain practical skills must be taught in labs, etc. But the vast majority of intellectual effort in a Harvard degree should already have all its coursework and testing available to everyone, and at reasonable cost. Otherwise it is not an open competition, it is an institution promoting socioeconomi status.