So they were effectively asking for the make and model.
There are non-certified authenticators which may have unfortunate behaviors here, such as having attestations containing a hardware serial number. Some browsers maintain a list and will simply block attestations from these authenticators. Some will prompt no matter what.
There is also a bit of an 'Open Web' philosophy at play here - websites often do not have a reason to make security decisions around the make and models of keys. Having an additional prompt in a user conversion path discourages asking for information they don't need, particularly information which could be used to give some users a worse experience and some vendors a strong 'first-mover' market advantage.
In fact, the motivator for asking for this attestation is often for self-service account management. If I have two entries for registered credentials, it is nice if I have some way to differentiate them, such as knowing one of them is a Yubico 5Ci while the other is an iPhone.
Many parties (including Google) seem to have moved to using an AAGUID lookup table to populate this screen in order to avoid the attestation prompt. It also winds up being more reliable, as software authenticators typically do not provide attestations today.
