The basis requirement for citizenship is stated as,
"You have been a permanent resident for at least 5 years and meet all other eligibility requirements."
Now this requirement make perfect sense for people who are able to get the green card without wait.
The employment based green card category has wait time for 5 - 10 year based on the sub-category.
Where as the people who are able to file green card concurrently gets their green card in 6 months to year. And they can become citizen in next 5 years.
We suffers through the long wait time to get their green first and then wait for another 5 years to become citizen.
The basic requirement should be modified to look PERM or I-140 approval date so that we can get a fair chance and equality.