All depends.
Any belt driven component will
1) wear the belt
2) load the belt
3) overloads & siezures will certainly quickly destroy / damage a belt
Power steering pumps by nature introduce more rapidly varying loads than a waterpump or alternator.
Vehicles that do lots of slow, lock to lock manoevers will certainly load the belt heavily.
I replace auxialry drive belts every 3 years regardless of their condition. Compared to older vehicles designs of the 80s/90s modern cars generally use just the belt for alternator, power steering, aircon and water pump (unless water pump is driven by cam belt, which is a daft idea imho). Of the belt designs that do this then the ones that fail most often are the "double sided Poly-V belts" that have ribs and drive components from both sides of the belt.
The Fiat 5 20V cylinder Coupe, Marea, Bravo etc. engines use these double sides belts. When these belts fail it is very common for the outer ribs to break off and get them selves ingested and wrapped around behind the crakshaft pulley. As more gets pulled in the cam belt gets lifted and the cam timing slips. With luck you will see the engine managment light come on as the camshaft phase sensor detects incorrect timing before the valves hit the pistons. Has happened to me on our Fiat Cupe 20V. Although no damage was done we still had to have a new cambelt and pulleys fitted. NOT cheap.
