If you want better, then I think soil is better, because the roots will develop for seeking nutrition in soil. However, if you say, which works -- both can work.

I find that some plants do better in a water medium, and some are fine in a non-water medium.

If you are using a mix or soil medium, the moisture retention, humidity, and other factors can play a part, in particular for some cuttings that have a reputation of being a little harder to root.

The other thing to be sure of is, which part of the cutting you are burying. Many times, the instructions say "stick the cutting in the pot", which could mean almost anything. But for many plants, it really means, "stick the cutting in the pot up to at least 1 or 2 nodes".

There are some plants that will look all wilty and dead when trying to propagate them. You can have a time limit in which you will try to resuscitate that cutting but at the same time, many plant cuttings reach a level that looks like they are dead but then will recover with new growth.