Based on your recommendations I got a 1/4 turn sillcock to use for a washing machine supply, and was surprised to see how small the ID was. Photos show the IDs of three 1/4 turn valves I have--vastly different.

For my washing machine, it may be a moot point, as I don't care if it fills super fast, but I'm curious about why these valves are so different, and in general, does it matter? The new sillcock was inexpensive--maybe it's just cheap??

Thanks.

Most fixtures have a reduction on the fixture side itself, such as a toilet fill valve, or a shower mixing valve body with smaller internal channels, shower heads typically had a flow restrictor to attain low flow.

There are times you want as much flow as you can get, such as a tub spout filling a bath tub, or a hose bib for filling a large swimming pool. A restriction could mean waiting several times longer.

There are quarter turn hose bibs that are full port, get those if you want to maximize your flow rate/volume.

ditto

its got to do with the size of the valve body that the ball is inside of.
note the size of the red handle body as opposed to the size of the yellow handle body.

Remember that the size of the opening allows a certain amount of water to flow. Don't waste water if you can help it. The same applies to water pressure. Unnecessary pressure wastes water. Try to conserve water.

he only wants to fill his washing machine faster.

Fluid dynamics caused a liquid to flow faster when it encounters a smaller opening. The pressure drops and the velocity increases. Therefore, for a short distance the reduction has little effect on the flow.

Note that the valve with the yellow handle is 3/4" while the other two are 1/2" so there's an orange in the apple basket so to speak.

Good eye!