My suspicion is they are two different ways of expressing the same concept but I struggle to find confirmation to it.
These two types of wallets, mate, are not the same. They both offer new ways to manage Bitcoin compared to the original or legacy wallet, which was the first type of Bitcoin wallet. The HD (Hierarchical Deterministic) wallet, in particular, is now the standard format for creating wallets. A descriptor wallet, on the other hand, refers to a method of generating various wallets using scripts outlined in BIPs 380-386. Here's the main difference
In an HD wallet, different child public and private keys are generated from the same parent keys. This allows your wallet to create multiple wallets controlled by a single key or seed. You can easily access a specific child wallet by using its corresponding private key.
However, this isn't the case for descriptor wallets. While they also generate different child public and private keys using the output descriptor, you cannot export a single child private key.
Here's why
With descriptor wallets, you cannot export the private key for one address. This is because a child private key combined with the parent public key can be used to compute the parent private key (and hence all other child private keys). This is a risk inherent in BIP 32's unhardened derivation. As such, descriptor wallets disallow the export of child private keys in order to mitigate the risk of accidentally exposing the parent private key