If vendors agreed to a common prefix on all secret key values then it'd be easy for everyone to add checks, to everything. Something like "_SECRET88_".
Of course, then your secret key checker would need to build that string by concatenating so that it wouldn't set off itself.
More and more providers have been adding unique prefixes to their tokens and access keys which makes detection much easier. Ex, GitLab adds `glpat-` to their PAT.
A project I maintain, Gitleaks, can easily detect "unique" secrets and does a pretty good job at detecting "generic" secrets too. In this case, the generic gitleaks rule would have caught the secrets [1]. You can see the full rule definition here [2] and how the rule is constructed here [3].
Of course, then your secret key checker would need to build that string by concatenating so that it wouldn't set off itself.