Disagree about the security. I just found out last month how unsecure the use of paper checks actually are because they expose your bank account & routing number.
I had an old checking account that was dormant and I hadn't written any paper checks against it for 10 years. What then happened was a landscape service asked me for payment for some work so I had my credit-card ready to settle the bill but they surprised me by saying they would charge extra 3% fee for processing the card. However, they said there was no fee if I paid by paper check. I didn't want to pay hundreds extra in fees so I used that dormant checking account to pay them with a paper check. They cashed my check the next day and I didn't think anything about it.
About a month later, I saw a mysterious "e-check" that subtracted money from my dormant checking account! It was not ACH; it was a generated e-check from a billing service popular with adult companies. So somebody from the landscaping company used the numbers on the bottom of my paper check to generate a fake digital check. The thief was on a website that let you pay for a subscription by creating an echeck; the web form would have fields for entering anybody's bank routing # and account #. (Example: https://solutionscout.com/payment-processing/e-check/)
When I talked to Bank of America about the fraud, I asked the customer service representative if there was any security setting that would prevent fake checks like that from deducting money from the account. He said "no". The fake e-check even had a totally bogus check # that was out of sequence with my real checks and he said their system doesn't verify the sequential #s. Literally, you're powerless to stop it and the only thing you can do is let the fake e-checks steal your money -- and then later file a fraud claim hoping to get the money back!
Paper checks are flawed with a critical security hole by letting companies generate fake e-checks. This means the more paper checks you write and release out into the world, the more of your banking surface area is exposed for you to become a victim of fraud.