Unfortunately the "generous grants" often conflict with "free to work at their own pace". It's getting more common to find arrangements where PhD students essen

Unfortunately the "generous grants" often conflict with "free to work at their own pace". It's getting more common to find arrangements where PhD students essentially have a part-time job working for their RA funding. In the best case this overlaps with their own research, but sometimes doesn't, and may involve considerable additional work that doesn't really "count" as research. Particularly the case if you're funded on a DARPA grant, since those have very specific timelines and deliverables, plus days where you have to be ready for a "site visit" to demo things. Some industry grants are fairly hands-on as well, expecting the lab to basically lend out a PhD student to work part-time on a project the company wants completed. Though others are more hands-off and just donate a pile of money without demanding specific things in return.