But in apartments you may have neighbours left, right, opposite, top, bottom plus the corridor outside.

Landed doesn't mean no disturbance but the problem is less severe than apartments where neighbours from 2 floors away can disturb you. If you are sensitive to noise getting a landed property is the best option if you can afford it.

It will probably reduce, not eliminate the noise. Low frequency sounds are very hard to damp out. Unless the footstep noises bother you a lot just leave it instead of spending expensively on a partial solution.

Don't waste your money. They will probably throw into the dustbin.