First Things opines "As the authority of the Bible and tradition waned, liberal theology turned inward. Our feelings and experiences became the arbiters of true doctrine."
But it doesn't address the main question: why did the authority of the Bible wane?
It doesn't address that question, because it cannot afford to address that question.
The authority of the Bible and of Tradition waned because it became more and more obvious that the Bible was incomplete and inaccurate. Discoveries in the natural world, from astronomy to technology to the discovery of the New World itself, all demonstrated that the Bible was not capable of addressing the issues generated by our enormous bodies of growing knowledge. The Tradition of the men who took the Bible seriously and literally, the Fathers and Doctors of the Church, was likewise inadequate to deal with the situations created by the information our growing knowledge base had gathered.
In times past, Scripture verses could be used to directly address social issues. In a world with essentially no international trade, constant threat of famine, plague and war, how do we care for the poor, the orphan, the widow? The problems were obvious and ancient, the Scriptures directly addressed those obvious and ancient problems. Scripture quotes could always be found that were immediate, cogent, clear, precise, on-point, and directly addressed the situation at hand. For those few situations where Scripture might not have a direct point, the Fathers of the Church could explain direct connections between the social situation under discussion and the Scripture passages that could be used to address them.
None of that is true now. What Scripture directly, explicitly and cogently addresses the use of IVF, or analgesics and anesthetics, or drones or AI or electric vehicles versus internal combustion engines or the (in)validity of man-made global climate change or acid rain or CO2 emissions or nitrogen fertilizer and runoff or forest management or statistical analysis of crowd behaviour or data harvesting or international finance?
As new social issues arise, Scripture has to be "spiritualized" and "generalized" to have any hope of being relevant. But this "spiritualization" merely highlights that Scripture doesn't actually speak to the situation at all. It becomes immediately apparent that personal opinions are being masqueraded as bearing Scriptural authority. This leads everyone to believe that their personal opinions are actually Scripturally-based.
Now, this is not exactly a new problem. The ancient heretics who questioned whether the Holy Spirit was God, how the natures of the Christus worked, what books were actually part of Scripture, and myriad other questions, were in a similar boat. They raised these questions precisely because Scripture did not directly, explicitly, cogently address these questions. The call for the first five ecumenical councils of the Church could be laid at the door of the bishops who injected the first non-Scriptural word, "homoousios", into a Catholic creed. That decision, in May, 325 AD, started the slow disintegration of the authority of Scripture and Tradition.
Arius had, by opening a discussion on Christ's natures, demonstrated what is now obvious. Even by the 4th century, Scripture had started to become so divorced from the current social questions that Scripture was no longer able to directly address existing controversial issues. Scripture wasn't relevant. At least, it wasn't able to provide relevance by being used as a reference. The first ecumenical council, and the creed it produced, demonstrated that Scripture was insufficient, incomplete.
As time went on, that insufficiency was demonstrated again and again and again. As technology grew - ironically, a technology created in no small part by the Christian worldview - it became more and more clear that Scripture just wasn't up to the task. Tradition tried to paper over the increasingly large gaps, but it has proven unable to do an effective job. Tradition relies on a rationality that is impossible to maintain. Even Tradition itself cannot maintain it. As T. S. Eliot averred, the center cannot hold.
Human beings are biologically built to emote. Our hormones don't create in us a rational response, they create in us an emotional response. From the ground up, on a cellular level, we are emotional first. This is who we are. Rationality is an add-on, it is duct-tape. It can be applied, it can work for awhile, but it ultimately does not stick. It is a hard tool to learn, a hard tool to use consistently, and it takes great skill to apply correctly. When we see that Scripture cannot resolve our problems, to the extent that we have been previously convinced that it can, the revelation of its inadequacy makes us recoil in disgust. We feel lied to.
This is the source of agnosticism and atheism. It is not repugnance towards God, per se, but repugnance towards being lied to, and in that sense, as Aquinas would agree, it is a righteous anger. This is what angers Richard Dawkins: not God, but the claims made in God's name. He asserts over and over that he pursues the truth. Insofar as he does, he is a Christian theologian. But the (necessary) claims made in the name of Christian theology about the both the adequacy and the inerrancy of Scripture and Tradition - that is what his soul rebels against. He can see that those claims are not true. He was told that he was not alone, and now he suspects that it was all a lie. He is alone. He is angry with those who lied to him.
