iPhone 5s iOS 11 Update
iOS 10.3.3 could be the final version of iOS 10.
Apple hasn't confirmed an iOS 10.3.4 update and given how close we are to the release of iOS 11, we don't expect Apple to release another milestone iOS 10 update.
So, if you're dealing with iOS 10.3.3 problems, you might have to wait awhile for the next batch of bug fixes from Apple's engineers.
The iPhone 5s will get Apple's iOS 11 update when it arrives this fall. The device's predecessor, the iPhone 5, will not.
The official version of iOS 11 won't arrive until the fall but you can try the update right now thanks to the iPhone 5s' iOS 11 beta.
If you're interested in getting off iOS 10.3.3, you might think about giving the iOS 11 beta a try right now.