Google (top site for internet traffic) is defaulting to Passkeys: https://blog.google/technology/safety-security/passkeys-defa... (Gmail has over 1.8 billion active users as of 2023; 22.22% of the world's population uses Google's mail service, so this is material for Passkey uptake)

Amazon: https://www.aboutamazon.com/news/retail/amazon-passwordless-...

Uber: https://help.uber.com/riders/article/using-passkeys-to-sign-...

Ebay: https://www.ebay.com/help/account/signing-account/signing-ac...

Github: https://github.blog/2023-09-21-passkeys-are-generally-availa...

Link by Stripe: https://app.link.com/

Docusign: https://www.docusign.com/blog/docusign-customers-can-upgrade...

Tiktok: https://newsroom.tiktok.com/en-us/passkeys-fido-alliance (TikTok has over 1.677 billion users globally, out of which 1.1 billion are its monthly active users)

Google's Titan key now supports Passkeys if you need a secure hardware authenticator: https://www.wired.com/story/google-titan-security-key-passke... | https://store.google.com/us/product/titan_security_key?hl=en...