At my org they also organize the Thursday evening drinks session :)
We use Justworks and they do that all for us. You're technically an employee of Justworks, and their name shows up on your paychecks. You hook into their health and 401k benefits, and they check all the workplace safety boxes. For instance, they'll mail you posters you legally have to put up in your office to ensure you're telling employees about overtime. HR plays literally no role in any of time apart from maybe selecting the health plans, something we do once a year and roll over every time.
> ensuring that staff is well trained for their role
What does an HR person know about training for your role? Is HR cross-trained in engineering for instance? Seems wildly different from my experience. HR would ineffectively screen candidates and ask you about buzz words. So they'll ask "do you have experience in Javascript" and I'll say "no, but I have a lot of experience in Typescript" and they'll just screen me out because they'll have no context.
And HR staff is also much more social so they'll pick up on awkwardness and screen there as well, when in many fields like engineering, the tolerance of awkwardness is much higher.
IME they don't know anything about the training itself. But they don't work in a vacuum, so there will be training programs set up by "regular" staff, and HR will make sure that you have access to them, that you attend your training if it's mandatory, etc. They'll also ask you if you need any kind of training you're not getting, and figure out a way for you to get it. Again, this usually involves the "technical" staff. They're typically facilitators.
This is what I've noticed in two medium-sized companies in France.
Mostly true for big companies in the US as well.