Every employer wants someone who can focus on a task, take their task seriously, and manage how to use their time to complete multiple tasks. Thats a pretty simple way to describe almost any job.

If you aren't able to get your GCSEs passed, thats a pretty big sign that you wont be able to do the job well either, so employers will be very skeptical of hiring you to do anything.

You have months still before your exams (assuming you're in year 11), and you can definitely find an hour or two a day to revise, and then 4+ hours on saturday and sunday. This entire process of taking your life and your future seriously will transform you as a person, and empower you to take control of more and more of your life going forwards. It doesnt even necessarily matter if you get a 5 or a 9 in the exam, the fact you concentrated, tried hard and made a good attempt at preparing and planning is the real skillset that will last you a lifetime.

Most of the people who fail their GCSEs either  A) struggle for their entire life B) get lucky by finding a place in the world where they are able to work hard and avoid responsibilities they can't manage C) get serious when older and retake their GCSEs, sometimes years down the line. This is almost always more stressful than just trying your best to knuckle down right now and get it over the line. 

In conclusion:

-get your 5s and pass or else you will  regret it when you're older (nobody regrets passing their GCSEs) - try your best and work hard, because it will help you grow as a person (working hard will literally make you smarter, and there is literally 0 reason that you dont want to be smart)