Officially Speedup you Galaxy in 7 steps.

[Infinity9]

1. Open Settings 

2. About phone

3. Tap on build no. multiple times till you unlock Developer Options.

4. Go to developer Options (below about phone)

5. Find Windows animation, transition animation, and animator duration. 

6. Change all of them to .5x

7. Keep developer options turned 'on'.

Try it and comment if you find it useful.

[KUNAL_1]

If Developer mode enabled, will phone be covered under warranty?
As most says by enabling we lose the warranty, as enabling phone might open for vulnerabilities!

[Infinity9]

Not at all.

[Samsung_OneUi]

No we dont loose warrenty by using developer mode. Just keep turn off USB debugging option.