Prompt: When people succeed, it is because of hard work, l. Luck has nothing to do with success,. Do you agree or disagree with the quotation above?

I understand that you probably didn't write this, but for reference, those commas should be periods.

Competenceition in today's world is merciless, which derives in due to opportunities being far from plentiful.

Did you mean competition?

Under these circumstances, those who work incessantly have thrived where lucky individuals have failed to achieve magnificentremarkable results.

have - have parallel structure. Magnificent and remarkable have roughly similar meanings, but I think magnificent sounds a bit out of place. Just "good" would also be a fine choice.

To begin with, stories aboutbest-selling books abound in stories of influential CEOs who reached success by working hard abound in best-selling books.

"Stories of" sounds slightly better to me because you're literally talking about their stories (as opposed to stories related to but not of them).
I understand that you literally meant "abound" + "in best-selling books," but "abound in" (or alternatively, "abound with") is already a phrasal verb that means "to be filled with." So if you want to use the verb abound, it should be moved in front. Alternatively, just use another phrase.

Additionally, sports is another field in which a tremendous amount of work is needed for keepingto stay up to par with theirone's peers.

"Keep up to par" would need to take an object (e.g. "keep one's skills up to par"). You can't say "their" here because you didn't mention anyone in particular; you need to use "one's," where "one" refers to some non-specific person.

Cristiano Ronaldo, named by many as the greatest footballer of all time, has clearly talked many times about the strict daily routine whichthat led him to succeed in one of the most important sports in the world.

The as isn't strictly required, but it feels more natural to me to include it. If you don't want to have the as, I think you'd need to put quotes around "the greatest footballer of all time" or something.
I'm assuming "clearly" was supposed to denote that Ronaldo was clear about what he said, but if you say "clearly" there, it sounds like you are saying "without a doubt, he has talked about X." If you want to keep that nuance, I would rephrase as "has made it clear many times that it is his strict daily routine ...."
"Which" is for nonessential (nonrestrictive) clauses; here, you need to use "that."

Furthermore, Kobe Bryant, a basketball player who stunned the world with his record-breaking feats, is well-known for his discipline and commitment.

Not only is success relevant in finances and sports, but it is also is indispensable in science.

I think it may also sound a bit nicer to omit the "but" here.

The greatest minds of all time worked tirelessly forto enriching mankind knowledge the knowledge of mankind.

Newton was indeed one of a kind,; he single-handedly created differential calculus and laid the foundations of mechanics.

or: Newton was one of a kind, single-handedly creating differential calculus and laying the foundations of mechanics.
I don't quite understand what "indeed" was supposed to show here. If you could clarify, I would be happy to provide some alternate phrasing.

Such was the magnitude of this monumental achievements, that he worked on a daily basis for many years by himself for achieving these resultwhich he achieved working by himself on a daily basis for many years.

To conclude, hardly ever has someone reached histheir full potential without giving their best.

There are many success cases relaattributed to hard work in finances, sports and even sciences.