VPNs don’t help here, the website asks you for your driver’s license. Tbf giving your credit card to them is typically enough for them (big tech + govt) to construct a full profile of who you are anyway, and that was the original “age gate” – though there are some services that make CCs modestly privacy preserving – not the case for IDs
Well…
If you follow the link to fedidb, refer to the “mau” monthly active users. Do some brief math and realize that lemmy.world accounts for about 50% of all active users
Email market share is harder, but many estimate that Gmail accounts for over 40%. Many many orgs use Google apps to make custom branded gmails with their own domains too
This is the typical “business power law” that states that the top player should control about 50%, the second player about 25%, etc. This is just kinda how the world works