In Australia, you can transfer money from your bank account to theirs if you know the account number. (Knowing the account number does not allow you to take money out of their account.)
I pay everything online now. My one check per month is written to the local comic book shop - he’s too small an enterprise to make accepting plastic worthwhile.
In Spain, most small businesses wouldn’t even know how to deal with one. I don’t have a checkbook. The only time I’ve used checks in Spain they were cashier’s checks, specifically obtained for the occasion (one to pay for my car, one for my flat - which wasn’t even brought by me but by the bank providing my mortgage).
I’m now in Northern France. I’d previously been in another region (the Trois Frontiéres, near Basel) where I never saw anybody use checks; here they appear to be pretty common. There are signs in supermarkets offering to accept checks dated at the start of the following month and I saw someone trying to pay with a check in the self-scanner (not possible).
All my banking is done electronically.
The one exception is the check I write by SO every 1-12 months or whenever she remembers to put together my “invoice” for our shared living expenses.
She’s big on not only using checks, but physically hand delivering them to a teller in the small-town bank where she grew up 2 hours from NYC. Bills too. I don’t know how many times I’ve heard “you’re working from home today? Good! You can drop off the bill at Cablevision or PSE&G!”
One a month, to our condo association (which consists of 4 units).
The debit card and online banking has pretty much eliminated my need to write checks.
I write one for my rent and that’s pretty much it.
One or two a year. I have the same set of checks issued when my current bank account was new, 12 years ago.
Zero. Dropped bank accounts all together after a disagreement and snafu with BoA. At this point it would cost me maybe 150 bucks to clear it up, but nah. Don’t need a checking account, I’ve discovered, so screw 'em.
Just one on a regular basis - my son’s fiddle teacher gets a check monthly.
2 to 3 times a year I find someone that will only take cash or a check. That’s the only time I write one. The Florida DMV is one, they hate the credit cards that I use but will gladly take checks.
One a month to the cable company because my work phone is part of the bill and I want that portion paid separately.
One a year bonding/insurance. One takes online payments the other doesn’t.
A few times a year I send in a check for the SO’s child support, it can’t be paid any other way. If he’s on the road I transfer the money from his account to mine and send in the check.
Miscellaneous birthday, wedding, gifts. A few a year.
I still have some utilities that don’t take electronic payments (our apartment water bill for one) and then there are some where I have zero interest in letting them keep my CC or bank information on file.
Same.
I pay toll fees with a check. I use a check less than 12 times a year. My regular payments are made mainly through an online banking service.
There’s Paypal and the like, though most of the places I write checks to can’t handle that as far as I know (e.g. our cleaning lady). I should actually ask her if she happens to have Paypal, though I doubt it.
I could get my son to set up a Paypal account - and in fact I should, in case I ever need to get money to him quickly at college (though my fallback is to go to his credit union and deposit it there).
Of the folks who write a lot (like me), do most of you have school-age kids?
How do you handle bills etc.? cash?
Bank transfer using online banking.
Usually 4, one each week to the Church collection. However sometimes there is a second collection, so I put down 4-6. Now I hear my parish is going to edonate or something, so I may soon be down to zero. 
Couple a month - for doctor copays. Everything else, including my church donation, is electronic transfer.