I agree that, for most of human history, people organized their lives around myths and folklore. It reïnforced social values and gave people the purpose and significance they crave.
But with the advent of the 'secular' scientific method we had a new investigative modality, that dismissed unevidenced mythology. This has been extraordinarily fruitful, however, many feel the stark reality revealed renders them insignificant and without purpose.
Not sure why the scientific method is 'secular' unless in the sense that chimneys are secular or cornflakes are.
The 'scientific method' also didn't 'dismiss unevidenced mythology'. One of the primary reasons experimental methods became popular was due to a link to theology.h ey were widely mocked as useless at first, even the novel Gulliver's Travels contains a world that is mocking people who are caught up in useless scientific speculation.
Lining the fruits of the industrial and scientific revolutions to 'secularism' is very dubious as they very much emerged in a Christian context.
Again, good points, but knowledge and technology are utilitarian, they don't claim to give you meaning and purpose, nor is a divine necessary for eusocial values.
These don't give you meaning and purpose, which is why we have to invent meaning and purpose. A godless mythos is still a mythos.
Secular Humanists basically just adopted a godless form of cultural liberal Protestantism. Just keeping the values while rejecting the supernatural bits hardly makes 'true' rather than being just another myth. Liberal Protestantism turned into the Providential Deism of peole like Jefferson then people just replaced the Providential Deist god with a secular Idea of Progress (that basically casts Science and Reason as Divine Providence via meliorism).
"Science and reason" lead to as many illiberal ideologies as they have liberal ones which is not surprising as where they take you depends on your values.
The key Enlightenment value was Progress, and simply since The Enlightenment 'Progress' has probably been responsible for more deaths that all religions combined in human history: from The French Revolution to Peter the Great to Communism to the Iraq War and Afghanistan (although it is fair to note that the Enlightenment idea of progress was not exclusive to secular thinkers).