It's not the place that makes you successful, it's your efforts. Getting into the US alone won't change your life. You have to bring something with you. If you've got nothing, then, well, you've got nothing.
Efforts definitely count, and you can build a successful company anywhere(almost). That being said, if you're aiming to maximise the chances of success for a tech company, the US, specifically SV is your best bet. No other area in the world has the same level of VC and talent.
Talent of SV is also overrated. Smart people are available everywhere, many of them not interested in going to the US. Pay them reasonable salary and they will build you anything.