Android

Factory reset is probably all you need.

This wipes the user data partition, which deletes all your apps, and it also deletes any accounts on the phone.

Do that, then run the Universal Debloat Utility disabling only the "safe" category. https://github.com/0x192/universal-android-debloater

This is about the best you can easily do on Samsung, since they're a bit bloated. It's made a significant difference on some lower-end Sammy's of friends and family (like the A series).

Alternatively, if you don't want to reset everything, you can try uninstalling what you don't use (or anything that would be easy to reinstall), then run SD Maid and have it clean up orphans, etc. Then run Debloat.

Keep in mind that as your data partition fills up, it can slow the phone. I find that under about 15%-20% free space I start to see lags.

Not really. If you uninstalled all apps, you'd effectively end up in the same state as a clean install (modulo system settings). Reversely, if you did a clean wipe and then installed all of your apps again, you'd end up in roughly the same state as before.

In 9/10 cases, it's not the OS that's bogging down your device but the apps. Take a look at memory usage and uninstall or stop things you don't need running in the background.

I think it's likely updates. The phone was originally built with an earlier version of the OS in mind. Just a guess. I feel like this happens to all my phones eventually.

Fwiw I have an old s21 fe version that I still play with (I have a pixel 8 now) and it feels more sluggish than it used to.

If you'd install something like lineageOS you might be better off, because your phone doesn't have to run all the bloatware Samsung ships with their devices. Some nice features of the device may not work then, though. I run custom roms on all my android devices.

Up until December I was still using my old S10 without slowdown. Never factory reset, just debloated via adb and used KISS launcher (minimal mode). Since it was a snapdragon one, I couldn't unlock the bootloader to install a custom rom. Had I been able to, I wouldn't have bothered switching to a pixel and graphene os yet. Point being, if you debloat your phone using adb you should be fine in terms of slowdown. There's guides on GitHub for what packages to remove safely.

If you are able to unlock the bootloader and use a custom OS, even better.

I know this question was from last week, but I have an only slightly different angle that I'd like to share.

Android doesn't benefit from reinstallation in the same way that a PC does because it uses a different app model. A PC can slow down due to accumulation of useless junk files, plugins, and services running in the background that you no longer use. On Android, you can have junk apps, but Android does a good job of bringing them to your attention by requiring a notification while an app runs in the background or else the apps and services get heavily throttled to avoid using the CPU if the user doesn't access the app regularly. Android also provides clean removal of all files when you delete an application. Apps are very self-contained with few exceptions. If you removed all the apps you downloaded, the system is pretty much the same as its factory reset state.

In the really old days, a PC could slow down due to fragmentation of the files on the disc over years of use. This is no longer a significant problem because flash storage offers fast random access even to highly fragmented files. Manufacturers actually recommend against attempting to defragment this media.

depends

as long as it is an android image from the manufacturer for the drivers

beyond that the part that contains the operating system the memory module is the same as desktop/ laptop, auto, and any other computers in one regard

anything that contains, reads, or writes data will eventually lose integrity usually at 2-3 years sometimes up to five years