Why is is so hard to find a good job?

It's hard because you're 18 and have no job skills. Entry level jobs are where you start.

good jobs usually require some skills and expertise, at 18 you don't have those unless you are really special, you need to find what you are good at and then get more training in that field to get a better job

It's a typical entry level job for an 18 year old. You don't yet have skills to make someone want to hire you for a better job. That'a why you need to get some education or training that will qualify you for a better job.

Competition. Workplace Darwinism is a reality. What have you done to prepare to compete for a good job? Have you gotten good grades and done something productive in school? How are your soft skills? Can you complete a coherent thought in writing and in speech? Your poor writing sample here at least suggests that you cannot.

If yes, keep job hunting and work on your application. If no, use the rest of your youth to improve yourself and make yourself more employable.

Because everyone wants a good job, so theres many more people vying for the best positions than there are positions available.

Because you're still only 18, and therefore still only at the bottom of the career ladder until you gain more life experience + perhaps some more qualifications that'll lead to better jobs (e.g. Joinery/Carpentry, Metalwork, Plumbing, electrical, Marketing, etc)...... even Sean Hannity the Fox News host used to wait tables before eventually going on to become the highest paid news host in the US....

Meanwhile, this guy started off as a Firefighter in the military, got sick of it, started an SEO & Marketing company instead......
https://www.youtube.com/watch?v=2FSBPtW68Jc

The reality is being 18 years old and joining the work force without an education and little work experience will get you nowhere. To be 18 and finding a career where you can make a comfortable living is nearly impossible these days. It's all about NETWORKING and about who you know in life. I talked to customers when I used to be a cashier and that's how i eventually started the career i have now as a plumber. Another friend of mine was 18 and met a gentlemen while working at the gym and eventually he got my friend into Heavy Highway Constructiom Laborers Union. My friend was 18 making $38.35 an hour but that's an unskilled labor job with no advancement. I started my career making just $500 a week. And in 5 years after my apprenticeship i'll be set for life

I was in your shoes at one time too. I tried looking everywhere but everyone wanted experience. I ended up working part time at a pizza parlor and went to vocational school. Then landed an office job I liked and worked my way up a bit. You should try some classes or volunteer work to add to your resume. Best of luck

You need a trade. Look up JobCorps on-line. You my qualify for free training to get a better job/career. Electricians, for instance, make more than a teacher.

So... you have no degree nor any kind of professional formation, nor any professional experience, and you were expecting to find better than a cashier or a McDonald's job?
It's time to wake up ! Put an end to your crazy delusions.
In your case you're already "lucky" to have a cashier job, it could have been worse.

NAFTA. Manufacturing jobs used to be good jobs before NAFTA sent them all to China.