The big question is, will the aid actually match it?
This concept of prescriptive targets might be worth talking about in detail.
As I understand it, NA-NL2 is currently the most common formula for for fitting HAs. This link has an overview:
There are other methods, but the general idea is that you can derive the desired amplification in each frequency band from an audiogram. And widely-adopted formulas for doing this exist.
But the question remains, is the device actually capable of delivering that amplification in each frequency band, or is it not calibrated correctly to deliver the desired results from the derived amplification levels given your specific ear anatomy (the shape of which will resonate at certain frequencies, increasing and decreasing volumes in certain bands)?
Any current-generation OTC device will be attempting to match a given audiogram, but many - or even most - may not be capable of (or may programmed in software to stop short of) hitting prescriptive targets the way an audiologist-fitted HA can.
To your question, an apparently underperforming OTC aid might be performing as designed while still amplifying at levels significantly lower than the expected amplification using industry-standard formulas. Is this to please new HA users? For safety? To ensure cheaper devices can’t measure up to “premium” ones? Will it stay that way as the market matures (assuming it does)? Hard to say.