I've also think this is a bad behaviour. If people are using hte Multiple feature, I think they are using it wrong, as sprite atlases do the same thing automatically with more control on each individual sprite, without concerning on how they will be packed in the atlas texture.

Using Multiple mode should be a very specific use case, as sprite atlas will always be a much better way to use "multiple sprites" in a single texture.

So puttin mutliple mode by default, I suggest you (Unity staff) to check how many projects now have overriden the default importer settings. You will see that this change is a completelly mistake

I would love to see test group you used for determining this outcome. Its bull*hit

Why is this not a toggle that we can set?

We will break everything for one part of the users to make the situation easier for another part of the users. Facepalm. How about adding a standard sprite import setting for the entire project?

This is not an acceptable resolution. Previously if you changed the texture type from Default to Sprite (2D and UI) it would then create a sprite for you that was ready to use because Sprite Mode defaulted to Single.

Because Sprite Mode now defaults to Multiple, when you change your texture type to 2D, nothing happens. No sprite is created until you install the Sprite Editor package, open the Sprite Editor, and click and drag a rectangle that covers the entire texture. I've been using Unity for more than 10 years and I had no idea that I needed to do this or how.

This is significantly more work than it was previously, and it's not explained what changed exactly and what you now need to do to get a sprite. I expect like me lots of other users will get confused about this new behaviour and spend a lot of time searching on line what's wrong, thinking it's a bug.

By default it should *create a useable sprite* and if you do indeed want to define multiple sprites, THEN you take the extra steps of tweaking the range so it doesn't cover the entire texture / add extra ranges, instead of having it default to doing nothing and requiring everybody to take extra steps just so it does the default / produces a usable sprite at all.

Please either revert the sprite mode to Single or have Multiple produce a usable sprite that covers the entire texture by default to make this workflow as clear / convenient as it was before.