What makes a good 1-1? How important are they as a CB strategy?

It's a super open ended question and I know there's lots already on this, but would love any and all opinions around the topic. Some specific sub-questions I have:

• How valuable are 1-1s for new-EAs? In terms of building EA connections, feeling apart of the community, career value/measured impact, etc?
• Are intro 1-1s better than career specific 1-1s for early stage EAs? 
• What do good 1-1s look like virtually (over Zoom, etc)?
• Should they be structured (ex. going through a document) or unstructured?
• Should there be follow up? Does it make a difference in terms of the participants further engagement in EA? 
• What are ways to improve the quality / outcomes of 1-1s?
• Are 1-1's 'worth it'? 
  • Should we just have a sink-or-swim  mindset where people have to get further involved in EA only by their own effort?

I'd also love just general reflections on how you do 1-1s, what makes them 'worth it', and general advice.