activity monitor showing cached files even after deleting them what should i do

It seems that you may be confusing “cached files” as shown in Activity Monitor, with “cache files”. You can delete the latter but not the former.

The “cached files” mentioned in Activity Monitor are files that were used and the OS keeps in memory, to permit quicker access if they are used again. You should not try to free memory because the OS manages it, and using anything that tries to free or purge memory works against the OS and may result in worse performance and crashes.

Do not Micro- Manage the Cache files

The Operating System does that, without the need of any user interventions

I might be more concerned in the Memory Pressure

If it showing Green - you are fine

If it is showing Orange or Red - then it would be of concern