The cloaking field makes it a lot safer to travel and a lot easier to get the jump on enemies. The carrying capacity upgrade helps you go on longer hunts without having to make a return trip. The damage and rate of fire upgrades are very straightforward, allowing you to defeat machines in a shorter amount of time. There's also the upgrades, which can be either a boost to your damage, rate of fire, an increase to your carrying capacity or a unique technology such as the cloaking field. This lets you to sneak up on enemies much easier, allowing you to use Silent Strike more often.
One such ability is Low Profile, which makes you less visible when you're crouching. However, on its own it's mediocre at best, so you have to get other abilities to make it more effective. Enemies that would've taken a lot of effort to beat previously, can now be taken out in one hit. There's Silent Strike, which lets you perform silent takedowns on enemies, both robotic and human. In Horizon Zero Dawn Each upgrade and new skill unlock actually helps you become a more efficient hunter. Each upgrade and skill feels meaningful Most games nowadays are plagued by needlessly high level caps, useless skills and meaningless upgrades.
