Syrian Army took far higher losses and still won.
Anyways Taliban losses are higher than ANSF as confirmed by US Resolute Mission.
You are comparing a National army, An Institute with 70 Years of existence and experience of Full Scale wars, Counter Insurgencies and War against Terrorists and full cover and empowerment by Federal Government with well funded budget and close relations with Russian block.
With this rag tag security apparatus formed by occupying forces just 17 years ago without any in house doctrine or experience. You know very well the old Afghan army was totally disbanded and capitulated in the 90s and this new force came to existence just recently.
Just the word "Army" Doesn't mean the organization becomes one. The armies like we have in our countries like your army or our army are powerful institutes with decades of experience, Structure, Relations, Doctrines etc.
ANA is nothing like them. And you cant blame the Americans, You cannot simply raise a professional army from the ground and thin air.
What best they can do? Find people of Influence around the Country and then use their influence to get loyalty of the locals who are loyal to those locals to join the band they named as Army. and some youngsters who are ambitious to study in the Army institutes also supervised by foreign powers. because their are no local military academics infrastructure. What will be they indoctrinated for?
Take your country for example. Your Soldiers fight for "Bharat Mata", The country The mother land, Then the institute the pride of the nation, being part of it a privilege felt, the sense of being protectors of independence of the people, 70 years of indoctrination of the whole nation about the image of the military and Independence of the country and a cause to defend it. Thats how you make SOLDIERS and ARMY.
Thats the case with Syrian Army, Unless it is completely Disbanded and Capitulated, No matter how bad you beat it, it will get stronger and more soldiers it looses more morale it will get, they pride of nation defenders of country, Repelling the foreign invaders sort of Doctrine that pulls even more youngsters to join in.
Same is unfortunately not true if you are enlisted due to your Tribal chief holding an office in capital managed and run by foreign forces like Afghanistan