Of course, you will notice that, but you still need to be careful on servers with such mods, as other players will not mind stealing something valuable from you.
Moreover, the mod even implements a special mechanic in this regard, which should be taken into account: any player can steal something from your new backpack if they come up from behind. Your backpack is seen not only by you when you press F5 and switch to the third-person view but also by other players. It can boast a high quality level and pleasant color scheme but still does not load your system, does not focus on HD graphics, and harmoniously fits with the vanilla style of Minecraft. The first thing that catches one's eye is the visual side of the new content.
We suggest you read our overview of a mod called Backpacked, which is among the best add-ons related to backpacks. So the doubt immediately arises as to whether these mods are faithful to the vanilla Minecraft. But even they are, for the most part, far from reality, as the backpacks they contain feature a huge number of extra slots, a not particularly pleasant appearance, and the capacity of carrying pocket furnaces and various devices. However, there are only a few of them that can be considered interesting, high-quality, and useful. There are a lot of standard backpacks for Minecraft, as the mods adding them are numerous.