Yeah I totally get what you mean. If you're working in-house with a large, distributed team this can be a huge problem. I don't have a silver-bullet solution but I'll throw some resources in the mix which will hopefully provide some help.

For qualitative research, Dovetail and Userbit are great purpose-built options. I use Userbit as its pricing is more attractive to smaller teams but have only heard good things about Dovetail. In both cases the biggest draw is being able to record user interviews, tag and highlight trends and monitor over time.

You may have seen a Notion template posted on DN yesterday by Inês Duvergé. This is a great example of how to use Notion for Qualitative Research processes. The result overtime would make it really easy for new hires to consume as the structure would be consistent.

As for quantitative research, this can be a bit trickier to store because I suppose it depends exercise/activity. For example, Analytics, Surveys and Tree Tests are likely facilitated through different services which means the simplest solution is storing the exported file (if it has this functionality) in Google Drive or Dropbox. While this is a fairly manual process, if organised efficiently this might work well for your team's needs. Ideally someone has created summarised reports which should help provide the necessary context of the contents of the repository.

Hope this braindump helped someone out there!