No, this was only true in the Middle Ages. In the era of Ancient Greece and Ancient Rome, pitched battles were the norm since the Greeks lacked the resources to fight lengthy campaigns and so preferred betting most conflicts on a single pitched battle. It wasn't until the entry of Persia that long-term campaigns became the new established norm for Greek military practice. I mean the Phalanx was developed by the Greeks due to their preference for pitched battles, which the Macedonians improved upon. The only Greek people besides the Macedonians who ever had any cavalry worth mentioning and in numbers worth using in battle, were the city-states of the Thessalian Plains, most famously, Thebes where the first elite Greek unit of cavalry was created. The Sacred Band of Thebes. Phillip II and then Alexander the Great modeled their own elite cavalry units off of their methods.
Same as the Romans. Pitched battles were the norm, and they were preferred since Legions were trained specifically to fight in pitched battles which is where there advantage lay. Most of the "barbarian" tribes Rome fought, also preferred pitched battles due to this being central to their warrior culture, being Celtic Gaulish and Germanic culture.
Rome never possessed their own elite cavalry units until their Byzantine Empire days, before that, they were almost entirely made of 'barbarian" auxiliaries contracted for a certain amount of time to provide military service. They didn't make their own cavalry until the Eastern Emperor Leo I, (457-474 A.D.), which he did only because of the constant issues he was having with his Gothic generals and auxiliary units. That and Emperor Valens death during a Gothic revolt in 378 during the Battle of Adrianople was still fresh on their minds. Emperor Theodosius, who took power after Valens, after successfully starving out most of the Gothic rebels under Fritigern, attempted to make an elite cavalry unit but spent a good portion of his reign fighting usurpers, the most famous of these being Magnus Maximus and Eugenius with his Frankish right-hand man, Arbogast. Then he needed to keep large contingents of Gothic auxiliary cavalry on his eastern borders with the Sasanian Empire, who were still fighting frequent border clashes despite no outright war being declared. That, and the conflicts with the Persians over Armenia were still fresh in everyone's minds.
Theodosius attempted but never found the time to complete the attempt due to him being on one battlefield or another for the majority of his reign. His last series of battles were in 394, and then he died in 395. Man never had the time. Hell, another good example, Justinian the Great's main general, Belisarius, considered one of the best generals in all of the Early Middle Ages, his armies he marched to reconquer most of the Western Empire's lost territory from the Vandals and the Ostrogoths...his army was 2/3's cavalry. Then you have the early Muslims during the Rashidun Caliphate, the empire Muhammad's religious conquests eventually created, however short lived, their best general was Khalid ibn al-Walid, he was considered their greatest Muslims general of that entire era, and his speciality was using cavalry in unorthodox ways. He was so feared and respected on the battlefield, he was called the Sword of God.
So, The Ancient or Antiquity Era as some call it, warfare was predominantly settled by pitched battles in Europe. And lol, in China, siege battles were far, far less common than pitched battles. So again, the only time sieges were more common was in the Middle Ages.