One of the common reasons for a slow smartphone performance is having too many apps installed and running in the background. These apps consume the device's memory (RAM) and CPU resources, which can affect the speed and responsiveness of the phone. Rebooting the phone can temporarily clear the RAM and stop some background processes, but they may resume after a while. Connecting to a different network does not affect the performance of the phone, unless the network is congested or has a poor signal. The user can improve the phone's performance by uninstalling unused apps, clearing app caches, and restricting background activities12. Malware can also slow down a phone, but it is not the most likely cause in this scenario, as the user does not report any other symptoms of infection, such as pop-ups, battery drain, or data usage spikes3.
Jailbreaking a phone can also affect its performance, but it is not a cause, rather a consequence, of the user's actions. Jailbreaking is the process of removing the manufacturer's restrictions on a phone, which allows the user to install unauthorized apps, customize the system, and access root privileges4. However, jailbreaking also exposes the phone to security risks, voids the warranty, and may cause instability or compatibility issues5.
References1: Speed up a slow Android device - Android Help - Google Help2: Why your phone slows down over time and what you can do to stop it | TechRadar3: How to tell if your phone has a virus | Norton4: What is Jailbreaking? - Definition from Techopedia5: What is Jailbreaking an iPhone? - Lifewire