Need opinion on creating a password manager

I am working on a project of creating a password manager which lets you generate a unique email and fake details to fill along with the password cause most password manager only let you generate a password but you are still using your main mail in all the websites This will prevent mail spam cause you will get a separate mail account for every website you register and you can get access to it’s inbox and mail password Also after registering you will get a private RSA Key which can’t be cracked and which won’t be stored in the server so even if whole website got hacked there is no way the hackers can retrive the passwords cause they need the private key to decrypt the password and every user will have a separate private key What do you think of the idea should i proceed with creating it or is it just waste of time?