Although the arch is a common feature of the architectures of many cultures, there have been others which seldom or never used it. The "ancient Greeks" seem to have ignored the arch, although some of them had mathematical knowledge which might have helped in design and construction. The picture shows a building which borrows Greek ideas.
The beam is attractively simple, deceptively simple, and very limiting. By rejecting the arch in favour of a beam, we relinquish the ability to use the horizontal strength of the ground, resulting in forces in the structure that are far greater than the actual loads. And the forces within a beam are not easy to calculate. On the other hand, the horizontal thrust generated by arches and domes gives rise to problems, as we see from the buttresses of large gothic cathedrals. It is easier to work with vertical forces in the ground than with sloping ones.
So when we look at a structure using stone beams, we will always see short spans, heavy lintels, and probably a great number of uprights. Building a vast empty roofed space using stone beams is out of the question.
Here are pictures of one of the oldest structures in this web-site - a dolmen in Jersey. It is possibly about 5000 years old. It was a burial chamber, and was covered with a mound of earth. Some of the stones are not in their original position. It comprises a series of large slabs resting on two rows of stones, forming a long tunnel. The structure is very crude.. The view along the tunnel is interrupted by ferns.
Look at Stonehenge, an ancient Egyptian temple, or an ancient Greek temple. There must have been few "seats with a good view" in some of these many-pillared structures. Perhaps the concepts of worship were such that viewing by a congregation was not an important consideration. On the other hand, the practice might have been a result of the architecture.
A place where you definitely need to see well is a theatre. Greek theatres, in fact, were outdoor constructions, with no attempt at a roof, often built into a hillside, unlike the constructed Roman amphitheatres.
With an arch you can build centring and use it as ramps to carry up the voussoirs one by one. With a beam it is all or nothing; a straight lift, unless you build ramps which do nothing for the structure itself. The beam is one massive object: you cannot break it down into convenient blocks. The arch wins every time.
Here is a view from high on St Peter's, Rome. The colonnade is rather like a gigantic version of Stonehenge, artistically far more sophisticated, but in engineering terms, not so very different. Some people refer to architecture based on pillars and beams as trabeated architecture, as opposed to that based on arches.
Classical forms can also be imposing, or decorative and attractive, if used on a smaller scale, but when you see a classical portico with fluted columns on the front of a small town house you might wonder if this is too far in the other direction.
At the same time that modern materials and computational methods have released architects from many old constraints, the ease of construction of reinforced concrete beams, pre-stressed concrete beams, and rolled steel joists, (RSJs), has led to the building of a vast number of rectangular buildings. Often these have lacked the multiplicity of details at different scales which allow the eye to take pleasure in viewing a building. But in the right hands, extreme simplicity can work very well. The second picture shows an older way of building.
This is, of course, a matter of opinion. You may prefer the relatively plain outside of the duomo in Siena, or you may prefer the ornate inside, packed with artefacts. You can even admire both, or neither. It seems that many people prefer fewer ornaments than in older times. Many medieval churches had numerous paintings on the walls, of which very few traces remain. Not many people would now approve of a proposal to cover these buildings with paintings again.
The influence of de Stijl, le Corbusier (Jeanneret), and other artists, architects and theoreticians may have lent authority to the modern movement. There is nothing wrong with rectangles, but any construction requires sensitive design if it is not to lead to boring or ugly buildings. Disciples do not always possess the artistry of the masters. Some people say that we are what we eat. You might just as well say that we are what we see, or even what we don't see, because everyone sees different things when looking at the same scene. The work of architects and builders may well have strong effects on the way people feel, though not necessarily in the intended ways.
Tourists know what they want to see, and it seldom includes modern buildings, even ones that are considered to be masterpieces.