The most blatant structural error in this surah is an absolute, irreconcilable contradiction between the beginning of the chapter and the very end regarding mandatory religious obligations.
Surah 73:1-3:
O you wrapped in garments! Stand [to pray] all night, except a little—half of it, or a little less...
The Abrogation
Surah 73:20:
Indeed, your Lord knows that you stand [in prayer] almost two-thirds of the night or half of it or a third of it... So recite what is easy [for you] of the Qur'an...
At the opening of the surah, God issues an absolute, uncompromising decree: Muhammad and his followers must spend half to two-thirds of every single night standing in prayer. This placed an exhausting, impossible physical burden on the early community.
Realizing this was completely unsustainable, the author inserts a massive correction in Verse 20, completely walking back the command because "Allah knows that there will be among you those who are ill and others traveling through the land... and others fighting in the cause of Allah."
An omniscient, timeless God would already know people get sick, travel, and fight before issuing a universal command. Changing a perpetual divine law mid-surah because of basic human limitations exposes a reactive text drafted via human trial and error.