About 10 years ago they provided medical data from the samples. I used 23 And Me too confirm that a health problem I’d recently been diagnosed with was hereditary. At the time I remember being asked if my sample could be used to aid the type of research the OP talks about and I agreed to it.
A couple of years ago, I think 23 And Me was bought out by Virgin Healthcare, at that point I asked them to destroy all my data was worried about it being used to increase the cost of or preclude health insurance.
For Firefox: uBlock origin (of course)
Privacy Badger - controls which sites are allowed to use cookies
Mind the time - tracks time spent on various Web sites
Video DownloadHelper - detects media and allows you to download and transcode it.
Bitwarden - password manager