Why do you think it would take several years?
There have been 20+ hardware exploits that Intel x86_64 CPUs are/were vulnerable to, most of which AMD x86_64 CPUs are not.
Several of the Intel architectural vunlnerabilities are for CPU's that are closing in on ten years old. AMD CPU's don't sell in the same quantities generally speaking. Comparatively, AMD CPU's are more obscure. Security through obscurity.