Everybody in the know, knows that x86 64 bit was held back to push Itanium, Intel was all about market segmentation, which is also why Celeron was amputated on for instance RAM compared to Pentium.
Market segmentation has a profit maximization motive. You are not allowed to use cheap parts for things that you are supposed to buy expensive parts for. Itanium was supposed to be the only viable CPU for servers, and keeping x86 32 bit was part of that strategy.
That AMD was successful with 64 bit, and Itanium failed was Karma as deserved for Intel.

Today it's obvious how moronic Intel's policy back then was, because even phones got 64 bit CPU's too back around 2009.
32 bits is simply too much of a limitation for many even pretty trivial tasks. And modern X86 chips are in fact NOT 64 bit anymore, but hybrids that handle tasks with 256 bits routinely, and some even with 512 bits, with instruction extensions that have become standard on both Intel and AMD

When AMD came with Ryzen Threadripper and Epyc, and prices scaled very proportionally to performance, and none were artificially hampered, it was such a nice breath of fresh air.