Strips are usually flexible to one dimension only, which is exactly she the direction of the LEDs can be significant. The most common types of strips have LEDs lighting upwards, so if for instance if you wish to enlighten a wheel you have to look for side-mounted or side-view strips to be able to shape them the right direction.
The carrying capacity of strips is generally very low. Heavy-duty strip lights are not usually sold for home use, but much rather for commercial use on ships and in factories for instance. In home use, where carrying capacity matters - on an edge of a stair for instance - the use of profiles is the common solution.
