Screwdriver point on HDD case. Rubber mallet impact on screwdriver head == dead HDD
There’s dead and then there’s dead.
A screwdriver through the case would (probably) prevent your average teenager from just plugging in the drive and reading the data. A lot of that data would survive though, an may be retrievable by specialists. If the data on there is valuable enough for someone to pay OnTrack a grand for (or engage the services of a criminal hacker), then you need to DBAN it / otherwise destroy it properly.
Plus of course, if you’re recycling your PCs by donating them to a charity or someone else who can reuse them, a properly flattened drive can be recommissioned.