Does not sound like a good idea to me.
Benefits of using a cloud-like solution:
- your passwords are synchronized and backed up automatically.
- you need Internet access whereas Keepass works offline
- exposing your passwords to hostile actors including authorities that can subpoena for the data
In case you are subject to an legal investigation in your home country, Google may have to surrender all data they have about you, including your E-mails, searches, location data etc. They already have too much information about you.
I can see a couple reasons for not using Google, but the biggest problem is that you don't "own" the Gmail account. It is a single point of failure. If you lose access to that account, then you lose access to your passwords. That can cause severe inconvenience.
You could be locked out of your account for several reasons, including misunderstandings.
- Example #1: suppose that people are complaining about spam allegedly sent by you, and your account is restricted/closed as a result. Guilty until proven innocent.
- Example #2: your account has been hacked and Google are making it difficult for you to prove your identity, keep asking supporting documents etc
You might be able to regain access to your account after perseverance, or maybe not. Remember, you don't own it. In fact, if you are using a free service they have even fewer obligations toward you. This is more a favor than a right (time to check the TOS again).
So now the question is, can you get round this problem ?
If you don't know your password, most websites have a reset feature whereby a link is sent to your E-mail address (more rarely, by SMS). But if the E-mail account on file is the gmail account, then you are still stuck. Only manual intervention by a human being can reinstate access to the website, and you'll have to repeat this with other parties.
Now you see how centralization can be a problem.