There is a lot we could get into here but perhaps as a starting point there is an important distinction to be made between using a design system in a regulated healthcare use case or an unregulated one.
The TLDR is pretty much using an off the shelf design system for healthcare products can be a starting point but unless it’s been make specifically for healthcare products and validated it’s going to need robust research and testing before it can used.
If it’s not covered by medical regulation then it’s pretty much the same as any other industry and some companies see research and testing as optional and may reach for an off the shelf design system thinking they will same time and money.
From my experience that is possible if they instead understand the problem and use cases/work flows the design system of being used to solve and know which patterns to employ.
The long form on the regulated health side starts with identifying when it’s going to be a regulated product or not. If it’s will be used in relation to the diagnosis, treatment of patients or management of health data some form of regulation likely applies that means it the product mist be based on evidenced user need, validated to mitigate risk and for usability under Software as a Medical Device(SaMD) or as a medical device under FDA(US), MDR(EU) or MHRA(UK) standards - usually an ISO or equivalent.
Effectively you have to have robust research to prove the need, evaluate design solutions and the end product is both ‘clinically safe’ and effective. You can’t make a marketing or clinical claim without evidence that has been reviewed by a regulatory body.
Human Factors(HF) as a profession exists as distinct from UX design pretty much because they have a higher threshold for evidencing risk, usability and safety needed to mirror the rigour of clinical studies and trials to prove efficacy.