as I believe humans to be social and compassionate by nature

It's best read as part of the broader debate about whether human nature pushes people into being cruel or generous or noble or something else, in the absence of social structure.

It's not even necessarily commentary on the average person, but whether a power vacuum would enable the worst among us to be even worse than they can be in a highly structured society. Bad people taking power can still happen in a group that is 90% good, if the cruel or evil or narcissistic will take control for their own ends, and the good aren't successful (or don't try) in maintaining social control for good.

The mistake people make is thinking its about humans in general rather than English grammar schoolboys specifically. I went to an English grammar school, those kids are selfish, spoilt, self aggrandising little shits and the book is horrifyingly accurate in its characterisation of them.

I assume by "of the time", you mean any time before you were born. The difference in their publication dates is nearly the current age of the United States.

Robinson Crusoe was first published in 1719 and is generally considered the first true English novel but otherwise sure.