In an old manual transmission, that's true. Modern cars have anti roll back systems. But also, use the hand brake.
Can't you use the clutch and foot brake smoothly enough to take off on a hill? Even a slippery one? Hand in your manual transmission driver's licence!
[Tidbit: where I live drivers are issued with different licences for manual and automatic cars. You have to pass the test in a manual car for that licence, otherwise you can only drive automatic cars.]
The funnest was uphill on snow from a dead stop with no weight on the bed. Luckily my truck had 4x4
Do most manual transmission cars now do this?
Honestly, how have automatics gotten worse in the past ten years?