There are a lot of ‘lurkers’, but less than 30 folks would be involved in the yearly holiday matching thread and sheet. Every self-professed EA I talked to at Google was involved in those campaigns, so I think that covers the most involved US Googlers.
Most people donated closer to 5-10% than Jeff or Oliver’s much higher amounts, that is for sure true.
So I think both your explanations are true. There are not that many EAs at Google (although I don’t think that’s surprising), and most donate much less than they likely could. I put myself in that bucket, as I donated around 20%, but likely could have done close to twice that. Although it would be hard for me to do that in recent years, as I switched to Waymo where I can’t sell my stock.
For EA folks in tech, I’m still giving mock interviews. I’m bumping this into quick takes because my post is several years old, and I don’t advertise it well.