The largest tech companies appear to be localized in the US, specifically the Bay Area and Washington.

Why haven't foreign tech companies achieved the same global market penetration and saturation as US-based firms?

Examples like Samsung, Spotify, HTC, Sony, Baidu don't seem to have the same market cap nor breadth or global reach of a Google, Apple, Amazon or Microsoft.

But those countries do have talented engineers and funds to succeed. So what's stopping them?