It really depends on what you’re printing, how strong you need it to be, and/or what axis you don’t mind looking uglier because of layer lines.
In this case OP might have been able to print it on a side with minimal supports, but the idea is that printing it at an angle turns things that would have been overhangs (which are hard for printers to do because of the melted plastic sagging) into upwards slopes. The alternative is adding support material that is intended to snap off (i.e. The block at the bottom of this picture), but those would be hard/impossible to remove in models like OP’s that would have supports inside the holes.
It really depends on what you’re printing, how strong you need it to be, and/or what axis you don’t mind looking uglier because of layer lines.
In this case OP might have been able to print it on a side with minimal supports, but the idea is that printing it at an angle turns things that would have been overhangs (which are hard for printers to do because of the melted plastic sagging) into upwards slopes. The alternative is adding support material that is intended to snap off (i.e. The block at the bottom of this picture), but those would be hard/impossible to remove in models like OP’s that would have supports inside the holes.