How can you explain the transition from Romanesque to Gothic in Western European architecture?

In those days in Europe there was no longer such a need for the construction of bulky buildings with thick fortress walls. Thus, the Gothic style gradually began to push back the Romanesque.
The most characteristic features of Gothic architecture in architecture were: rich decoration, elegance, striving to the height. On the other hand, the Gothic style emphasized the insignificance of man before God, and therefore, many temples were built of great height, with spiers-towers. Then, in the 15th and 16th centuries, the Gothic gave way to the Renaissance style.