and i bet it went like:

1. login on computer. click next mindlessly on setup flow.

2. use account

3. try to login on phone. click next mindlessly on setup flow again.

4. where's my data?! oh well, lost my old account. let's use the new one

5. eternal confusion while switching devices. never return to site again.

= 2.5 times per user

How often do you login to your Google account once logged in? I don't remember the last time Google asked me to login, because the session persists.

I hope that you properly segment your browsing then, because surely you don't browse the web while logged in to google?

Moving the goalposts to a data security and privacy concern from strong auth factors. I don’t care if Google has my browsing history. I do care if someone else can log into my account, or ease of managing my own credentials. Auth protects you from others, data security and privacy measures protect you from the counterparty.

Not moving the goalposts. Just stating why you'd want to login often, or solve it in some other way.