For your reference, there are various reasons for this issue:
1. The system will perform a series of self-checks and initialization when you start the Redmi A3, such as checking hardware devices, loading drivers, and initializing memory. These steps will take some time, especially if the phone's hardware is outdated or has issues;
2. The system will load various pre-installed applications, services, and system processes as your phone boots up. If there are a large number of installed applications, or if these applications require significant initialization work at startup, it will extend the boot time;
3. The system will perform optimization tasks during startup, such as optimizing application caches and checking the integrity of the file system, which will also cause a long boot time.