The general view is that this early atmosphere would’ve consisted of carbon dioxide, water vapor and nitrogen. If you reproduce the experiment under these conditions you get cyanide and formaldehyde.
Although these are organic molecules, they certainly do not support living cells, rather having a completely opposite effect. Formaldehyde is so toxic that it’s not even allowed in many labs. Just opening a bottle can destroy proteins. Cyanide gas has been used through history to execute prisoners by gassing them to death. Mixing the two together creates embalming fluid.
In 1995 Science magazine said that most experts now dismiss the experiment because “the early atmosphere looked nothing like the Miller Urey simulation”.
Another objection to this experiment was the continuous cycle that the elements were put through. Although it is believed that the early Earth did have frequent lightning storms, it would not have produced the amount of amino acids that the Miller experiment did, however, it still could have produced amino acids.