I think that Itanium had zero impact on anything (besides draining Intel for money) due to high cost and low performance.
It could not run x86 apps faster than x86 cpus, so it didn't compete in the MS Windows world. Itanium was a headache for compiler writers as it was very difficult to optimize for, so it was difficult to get good performance out of Itanium and difficult to emulate x86.
Itanium was introduced after the dot-com crash, so the marked was flooded with cheap slightly used SPARC systems, putting even more pressure on price.
This is unlike when Apple introduced Macs with PowerPC cpus: they had much higher performance than the 68040 cpu they replaced. PowerPC was price competetive and easy to write optimizing compilers for.
Itanium itself did nothing. But Itanium announcement killed basically killed MIPS, Alpha and PA-RISC. Why invest money into MIPS and Alpha when Intanium is gone come out and destroy everything with its superior performance.
So ironically announcing Itanium was genius, but then they should have just canceled it.
It could not run x86 apps faster than x86 cpus, so it didn't compete in the MS Windows world. Itanium was a headache for compiler writers as it was very difficult to optimize for, so it was difficult to get good performance out of Itanium and difficult to emulate x86.
Itanium was introduced after the dot-com crash, so the marked was flooded with cheap slightly used SPARC systems, putting even more pressure on price.
This is unlike when Apple introduced Macs with PowerPC cpus: they had much higher performance than the 68040 cpu they replaced. PowerPC was price competetive and easy to write optimizing compilers for.