“We have been mistreated, abused and oppressed. They have benefited from our suffering and we must act now!” whats the explanation?

that Him/her/they Have been mistreated and abused! Act now or this will continue, and him her, or they, will be suffering, that abusive person will have it's consequences

The speaker has been oppressed, mistreated and abused, all for the abuser to get good things from it. The speaker is saying how they have had enough and are going to fight back

Explanation: The word placement and language used suggests abuse and suffering, and by saying ‘we must act now!’ Suggests they are going to fight back in hopes of help or rights.

I hope I answered your question :/

faulty parallelism is a construction in which two or more parts of a sentence are equivalent in meaning but not grammatically similar in form.

the correct version of this faulty parallelism in the sentence is:

the hikers knew that the hike was six miles, that it usually required the entire day, and it would not be wise to start after 10: 00 a.m.

the problem is the last sentence, the first two have a basic subject+verb+object structure.

so, to give a proper balance to the structure, or better said, to give a parallel structure, we must write a basic s+v+o structure in all three sentences:

the hikers knew that the hike was six miles, that it usually required the entire day, and it would not be wise to start after 10: 00 a.m.