Really only needed with high-magnification optics and iron sights to have a consistent and precise cheekweld. Trying to shoot through a 40-power scope without a cheekweld can be difficult due to the very tiny exit pupil. The exit pupil is the actual shaft of light passing through the scope. My 10-40x56 has a 1.4mm exit pupil, so your eye has to be very precisely positioned behind the scope. With iron sights a consistent cheekweld is good for a consistent sight picture.
With low-power or unmagnified Optics cheekweld becomes irrelevant as your eye can be anywhere that you can see the retical - as long as the parallax is set correctly.
I like it on the Ruger Precision rimfire because I have the scope mounted so high.
https://youtu.be/VJJM4nQO7Kk