Buying AMD would be the biggest mistake Intel could ever make.
AMD is the only other company that is allowed to manufacture CPUs with the x86 instruction set without a license from Intel.
Why?
AMD was the first to manufacture an x86 cpu for 64 bit operations. They patented this which meant that Intel couldn’t make CPUs that could do 64 bit operations and so a deal was made.
AMD promised not to sue Intel for making their own 64 bit instruction set (which would have to be very similar to AMD’s own 64 bit instruction set) and Intel promised not to do the same against AMD when AMD made x86 CPUs.
If Intel bought AMD it would mean taking out the ONLY real competition Intel has ever had in x86. This would mean that Intel would be subject to monopoly laws all over the world and Intel would hence be heavily regulated in order to ensure that consumers wouldn’t be price gouged (or even worse x86 might be made free to use by other companies).
Intel needs AMD and they know it, else they would have bought up the company when their stock was below 1$ a couple of years ago.