To be honest, even if AMD does go bust, it's not like Intel is the only other company capable of producing silicon based tech...
If you remember the pre-AMD (as a genuine competitor) days you'd think so.
A Pentium 200MHz remained Intel's top spec general user chip for a very long time in 1996-1997 (after the earlier Pentiums had blown most all other competition away), once the K5 and then K6's appeared it made Intel up their game massively.
Same with Graphics cards after the fall of Voodoo.
Competition drives the market without it the pace of technology does (and has) significantly slow.