Is Afghanistan a war lab?

The United States secretary of defense, Jim Mattis has recently said that his country had not winning the war in Afghanistan.
The United States is involved in the longest war of its history. Washington made a coalition in late 2001 and invaded Afghanistan, after the 09/11 attacks on the World Trade Center twin towers to eliminate the al-Qaeda terrorist group that was believed to have been behind the attacks.
The people of Afghanistan tired of the extremist Taliban ruling, welcomed the invasion with the hope of being saved from long war. But unfortunately, the people’s hope was not fulfilled as the following years showed a different scenario. Quoted from (Afghanistan Times).
The United States came to Afghanistan with thousands of troops and spending huge amounts of dollars, failed to satisfy Afghans. The Taliban already weakened, became enough powerful to restart attacks on the people and the security forces of Afghanistan.
The former president, Hamid Karzai called several times when in office not to look for terrorism and insurgency in the poor villages of Afghanistan and the US-led coalition would better to target the bases of terrorism and extremis outside Afghan borders. But the US authorities did not want to listen.
The US policy unfortunately is not clear for the Afghans.
President Barack Obama announced in 2010 to withdraw his troops from Afghanistan by the end of 2014. Now, his successor President Donald Trump decides to send them back.
The Daesh terrorist group emerged in 2014 while the US had troops in Afghanistan. The US used its largest non-nuclear bomb under the pretext of targeting Daesh sanctuaries in the eastern province of Nangarhar, while no report of the Daesh casualties came out and even journalists were banned of visiting the scene.
The situation is deteriorating more day by day and the number of people being killed, injured, displaced and migrating abroad is increasing.
Now, Mattis says “we will correct this (the situation of war) as soon as possible”.
Considering all these, the people of Afghanistan ask a question that is their country a war laboratory for the powerful countries to test their war doctrines, strategies and sophisticated weapons in?