I wasn't giving an average, I was giving current processing times for the various steps assuming a current priority date and I called out the specific criticism you levied.
Go down to Employment Based and look at the priority dates (the priority date for employment based petitions is generally when you file for PERM with the Department of Labor, but there's some complexity here - although that should give you a good idea).
1st Preference (EB1) - extraordinary abilities, etc - is current for everyone except India and China, who are backed up to February 2022 filings.
2nd Preference (EB2) - masters degree or bachelors + 5 years work experience + a job that requires 5 years work experience - is backed up to January 2011 filings for India.
3rd Preference (EB3) - bachelors degree - is backed up to June 2012 filings for India, November 2018 filings for China but is current for anyone else who wants one.
[1] https://www.uscis.gov/green-card/green-card-processes-and-pr...
As someone going through the process right now, PERM is taking on average 12 months and the PWD has taken 6 months.
A request for evidence on PERM will extend that to 18 months on average and I-1485 is closer to 12 months but can be 18-24 months even if you are not from India/China.
Abolishing the country cap for Green Cards is something that should be done in tandem with either increasing the number of Employment Based Greencards or recapturing those that have been abandoned. Otherwise you just make the backlog everyone country's problem.
There are some steps they could take to make things easier like automatically sending EAP and AP when a I-140 is approved. It's ridiculous that these documents take so long to be issued.
Really though the United States should move to a points based system for Employment Immigration. If you look at EB3 it's a low bar compared to Canada/Australia. A points based system that is fast tracked like Canada's would be preferred to convoluted mess we have today.
Generally H-1B's can begin the green card process the moment they set foot in the US and it takes about 1.5-2 years (which is about 1y6m too long). The issue is not with the H-1B per se (quotas aside). The issue is that the green card process is too onerous and is subdivided by country of origin so some have to wait much longer than others.
Timeline:
1. Prepare PERM: 6 months.
2. File for DOL certification and get an approved ETA-9089: 120 days.
3. File for I-140 and I-485 concurrently assuming a current priority date with premium processing: 14 days for an approved I-140 and 6-12 months for an approved I-485 assuming no request for evidence. During this time you'll need to go in for biometrics appointment.