I pay for everything cash, so I have a low credit score.
How the fuck does that work?
Your credit score is the calculated chances that you'll stick to the terms if credit is offered. It's based on past performance and present (credit-based) circumstances. If you have no history, they can't score you. That's how the fuck that works.
I paid for my car cash, I pay my rent cash, I pay the cable company cash.
I have over $30k in the bank and I have monthly paychecks.
None of this hits your credit report, so it can't be used to score you. Money in the bank isn't reported and isn't scored. Paychecks and income aren't reported and aren't scored.
So I should have a much higher credit rating than someone who is constantly paying with credit cards in my opinion.
I wouldn't even mind so much, except that when renting a house they do a background check, and they expect to find a credit history, which I don't have.
Someone who is paying with credit cards and is keeping those accounts paid as agreed has a demonstrated history of responsibly managing their credit. You don't have that. That's why they score higher. You seem to want a credit score that's based on some personal knowledge of you, or your handshake, or a magic 8 ball or something. But that isn't how it works because we no longer live in villages of 20 families. Various items related to how you've handled credit/debt are reported to credit reporting agencies. Other companies (okay, pretty much just FICO) have developed various scoring models that take the information reported to the CRAs and turn that information into a single, simple number which represents the chances that you'll stick to the terms of credit is offered. Since they don't have any information about you, you don't get scored.
I pay for everything with credit cards, pay them off every month so there's no interest, and then I take free vacations with the reward points and cash back money. I have a long credit history showing that whenever someone provides me credit, I manage it responsibly and pay them on time as agreed. If someone is thinking about offering me credit, they can look at that long history (or just the number) and see that I'm a pretty safe bet. They can look at someone else who has a long history of failing to pay back everyone who lends them a dime and see that person is a huge risk. They look at you and they see a mystery box. What exactly would you expect to happen?