The risk isn’t just what the spring does but what happens to something caught in it. Springs can release energy a lot more quickly than a counterweight which can only accelerate a 9.8m/s/s, and therefore more risky to disable.
It also provides a constant force, whereas the force required to raise a garage door linearly decreases the higher it gets. With the consequence that a garage door with a failed motor would slam into its stops over your head rather then into the ground. Followed shortly thereafter by the now liberated counterweight slamming into the ground.
https://www.physics.smu.edu/scalise/www/misc/bricks.html
*Wrong link
Springs make a lot of sense from an installation perspective and can be easily tuned to match the specific door design, but if I was working from scratch on a DIY project I would prefer to use a counterweight if there was somewhere it fit.