They wouldn't be able to unrack and stand there either. Just standing with a very heavy barbell is extremely difficult (assuming an untrained person).

Seriously, go and try it, load up 100KG or roughly 225lbs on a barbell and just stand there with it. If you're already a big/heavy/trained guy, put 180KG or 400lbs.

It will probably be quite a surprising experience for you.

And I will say, that even when I was training for heavy squatting, standing there with a very heavy barbell on your back isn't fun at all, you have to have a very tight core, tensed muscles, breathing is much harder. i.e. just standing there is hard work and you want to get your 5 squats done asap. Also, it just plain hurts your back as the metal bar on your spine is painful!