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.
That’s a great idea and would require similar amounts of support, however there’s still going to be 90 degree overhangs that wouldn’t come out quite as nice as the orientation I used
The model in question only has 1 flat side, its end (which is the top in the photo). Every other side requires supports if it’s on the build plate because of the recess in the cap, and the cap being wider than the rest of the model
As a total beginner, it's not really clear to me what's meant here.
I read printing some things are better to print at an angle, like boxes, for additional strength.
Is that what's meant here?
In Orca slicer, if you use tree supports and hybrid, an option appears (advanced must be enabled) for something like "Essential supports only". It is so much better than spending all that time adding or blocking supports.
This model is almost entirely overhangs with small gaps between them, making support removal a pain. This way uses less filament and makes for better quality
This particular model would have lots of troublesome bridging if printed vertically, and would need supports along the entire length if printed horizontally.