It’s good that you wear out the phone til the end.

There are a few things that could help you speed up your phone by a lot. I am assuming you are on Android. If you are on Apple I can’t help you.

• Older Android version there is a cache partition. Clearing that will boost the phone’s speed by a lot. For that, google how to get into recovery on your phone and select “Clear cache” if that option is available. This is a safe operation where you lose nothing. DO NOT DO “Clear data” unless you want to lose all your data.
• Uninstall unnecessary browsers. Many browsers keep running in the background and consume resources. Most apps do that, but browsers consume lots of resources. Maybe one have the ones you can’t delete plus maybe one you like.
• Clear cache of the browser apps frequently. Especially Firefox seems to get slower the fuller the cache is. Also, cache consumes storage space.
• Disable preinstalled apps that you don’t use.
• Force close apps that you do use but that don’t need to be running in the background.
• On older Android versions install Greenify and let it kill all apps that have no business running in the background.