I understand that one should not use the same password everywhere, as stated here for instance.
Using the same password on several non-valuable sites may be considered acceptable: we simply do not care if they get compromised.
My question is about sites that I consider (wrongly?) as "very secure". I think it is very unlikely that my password would get compromised on Google, Github or Twitter for example.
Is it ok to use the same password for all these "secure" sites?
If that matters, suppose the password is very strong (>90 bits of entropy).