it is not only due to quotas. there is BS request for evidence as well as random changes. for example, they added some disease to the process (I believe gonorrhea or syphilis) and then the exam I took entering the process wasn't sufficient at the time they actually looked at the exam. then it took them a long time to send that notice, then I got the new exam and the clock started again adding around 6 months from the "we need you to test for a disease that can be easily treated if you had it" to the approval. this is with highly paid lawyer support.

EB immigrant visas take ages and then there's the archaic process of some poor schmuck sitting in an USCIS office asking the questions and checking boxes on a form that you submitted a second time...

From the p.o.v. of the person actually doing this, it takes years from the moment you apply to the moment you get the decision. This is what needs to change.