I am in my early 20ies and stopped Checking in online. I reserve seats when I book the flight and then go to the airport counter, that is a matter of 60s vs 2-3min online.
Why on earth wouldn't you check in online? An early check-in time makes you far less likely to be involuntarily denied boarding due to overbooking. (Having a seat helps too, but check-in time matters.) And if you have status, your chance of a free upgrade is in part based on check-in time.
If you want a paper boarding pass, check in 24 hrs early and select the option to pick up your boarding pass at the airport. ... Or get an electronic one (on your phone) just in case, and still go to the machine and print one out. You
can hold more than one boarding pass for yourself for the same flight. Happens all the time when they give a passenger with an electronic pass on their phone a paper pass at the gate, e.g., because they got an upgrade. I've used the pass on my phone after that's happened to me. The electronic one gets updated with the new seat automatically.