if your goal is to "earn money" then you can't rely on donations. specially for a new project and not for the first couple of years.
i want to create an open source bitcoin wallet with django framework that doesn't store any private key or phrase seed
you mean a "web wallet"?
i wouldn't call it secure at all, and i would think twice before using it specifically because it is relying on python.
by the way you can NOT claim a web wallet is open source ever. you can share the source code but nobody can verify if the domain they are accessing is actually running the same source code!
i know there is a lot of bitcoin wallet sites and they are popular
is it waste of time ?
yes, in my opinion it is a waste of time, because it is a "web wallet" and they are inherently unsafe so a new unknown one is not going to even get any attention.