There is almost no speed difference between sneaking only and sneaking and using items at the same time. This issue did not occur in 1.21.3.

How to reproduce:

1. Give yourself a usable item, for example an apple or a brush.
2. Start sneaking and moving forward.
3. While moving, start using the item.

Expected result:

The player would be slowed down a lot more when using items while sneaking, just like in previous versions.

Observed result:

The player is slowed down by a very small amount which is almost unnoticeable.