Unhappy with the WP Smush plugin

Good morning, the first to say that this text is translated by Google :slight_frown:

In search of a plugin to optimize my images since 80% of my web are images, I find that most blogs recommend this plugin.

Once installed and optimized all the images, I find that it has optimized almost nothing and in most online tests, it keeps telling me that my images are not optimized.

Data:

TOTAL SAVINGS 9.8 MB / 9.3%
ATTACHMENTS SUPER-SMUSHED 3405/3405 images

9,3% of 3405 images and only 9,8MB?

Anyway, I was expecting something else. The web https://gtmetrix.com/ optimizes me better.

Greetings.