I find it more convenient to use checks for some purchases but the thing that makes them bad for small businesses is banks charging insufficient fund fees to both the depositor and the person who wrote the check.
We bought some salsa from a local business yesterday and she takes Venmo, Zelle, or cash (not the app). If she took a check and it bounced (insufficient funds), then she would be out the money and probably a $12 fee besides.
https://www.bankofamerica.com/smallbusiness/resources/fees-a... It's interesting to see how business checking accounts have changed - there's no free level. You're charged a fee for every deposit past a certain number. I wonder how many small businesses are run now without a business checking account. But a credit union like Unitus https://www.unitusccu.com/business-checking/has free business checking accounts. Deposits are charged $.15 after the first 75 but if you sweep your electronic accounts (Cash app, Venmo, PayPal, etc.) in every other day you could take 5 of them.
I only converted about 2 years ago to taking pictures of checks and depositing them. It's much easier than going to the bank or mailing the deposits to Charles Schwab. Three of us did a joint purchase and I got a check from one. The other sent me payment via PayPal but PayPal took 3% as a fee. It didn't bother me enough to say something but it definitely didn't make me happy. It'd be nice to have an option that was zero-cost or $.10 fee per transaction. I bank with credit unions that don't have Zelle yet.