The best countries to open an internet company are as follows:
1. JAPAN
2. CHINA
3. SOUTH KOREA
4. UNITED STATES
5. GERMANY
6. SINGAPORE
7. UNITED KINGDOM
8. RUSSIA
9. SWITZERLAND
10. ISRAEL

No there is no significant disadvantages of being out of Silicon Valley to succeed, Infact there are numerous companies that have been successful outside the silicon valley: https://foundercollective.medium.com/startup-success-outside-silicon-valley-data-from-over-200-exits-in-17-cities-1872bf8e7619

Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath