Generally speaking, it has been considered by most societies to be more "prestigious" to win a battle in the field rather than a siege. However, as you have correctly stated, pre-modern era warfare mainly consisted of sieges. This is mainly due to the fact that compared to outfitting an armed force, construction of fortifications was far more cost-effective as well as being a long-lasting investment.

Also, from a Western European perspective (at the least), fortifications were as much a status symbol as builing grand churches or cathedrals, so every minor feudal lord would possess some sort of fort, whether it be a few ditches and packed earth mounds or tall stone walls and owers outfitted with crennellcations and holdings protecting a central keep.

Thus whenever a superior enemy would attack, they would have to spend enormous resources and lives assualting after weaking defenders enough by cutting them of from food and supplies or simply wait until they surrendered or the besieging force had eaten every thing in the region of the siege and was forced to leave, making siege warfare a game of attrition. Thus, in most cases, open battle simply didn't make sense, unless it was two larger entities of roughly equal strength and capabilities, who had decided to both field large levies to drive to other out of a region so they could safely lay siege to the others fortifications. eg. two rival kings.

The big changing point came about with the introduction of gunpowder and the development of standing professional armies under centralized national authorities. Artillery made earlier fortifications redundant, meaning much larger, more expensive and therefore fewer forts built around important strategic targets eg. cities or positions eg. overloking a beach, river crossing or mountain pass.

With larger, professional standing forces at a nations disposal, the scale and scope of battles increased, and therefore our perception of them, eg. the Battle of Agincourt 1415 has been estimated from anywhere between 5000-30 000 combatants in total, but by Napoleans time, the Grand Armee alone that marched on Russia in 1812 consisted of nearly 600 000 French and allied troops.

Therefore it can be seen that that the actual number of sieges and targets requiring a siege has reduced while the scale and scope of battle increased, therefore our perception of them as well.

Also, in modern times, the line between siege and battle has greatly blurred. In many ways, the entire Western front of the First World War could be perceived as two massive enemy forces besieging each other over a length of dual fortifications that stretched across northern France and Belgium.

-Will provide sources later