"but if VCs are already giving money to an established entrepreneur to do the same thing, why take a chance on a guy doing his coding in his house in a bathrobe"
Until you change this train of thought, you won't succeed. You need to convince yourself before you can convince others. If you can't even convince yourself, no one's going to buy into it.
If you can convince yourself that you have what it takes to succeed and that your secret sauce or magic formula is enough to staff off even the likes of google, then you'll still convincing others including those VCs you've mentioned.
Until you change this train of thought, you won't succeed. You need to convince yourself before you can convince others. If you can't even convince yourself, no one's going to buy into it.
If you can convince yourself that you have what it takes to succeed and that your secret sauce or magic formula is enough to staff off even the likes of google, then you'll still convincing others including those VCs you've mentioned.