CPU or GPU lag? no evidence

hi to all, i try to explain with my poor english!

After more then 600 hours play i have tried every possible settings without result. I'm always at bottom of the ranking becouse i don't kill and i die at first shot! Often i die when already under cover. Everyone look like a cheater for me! With the others BF i was always on top!

My pc is a little dated but i think is always a good pc:

i7 8700K (7th generation) 6 core 12 thread busted to 4.6ghz (not overclocked)

liquid heat sink

motherboard msi Z370 gaming pro carbon

16GB ram 3200 (uncore frequency 4.4ghz)

nvidia RTX 2080 

HD m2 ssd 970 evo plus 

800W 

I have tried any possible settings (i have read all blogs and saw any youtube video) and now i'm playing even with this one:

resultion 1600x900 60hz

minimum details and everything else set to off

vsync off

driver set to "prefer maximum performance"

no DLSS and no HDR

ecc. ecc.

PLEASE CONSIDER THIS: 

when i play i have 65% (max 80%) CPU usage and 25% GPU usage (never get cpu throttling)

wired lan and absolutely stable (1Gb + game setting) with no packet loss and 22ms ping

Then the question is... where is the problem? possible my PC is so dated???? is a CPU or a GPU problem?

I have to change cpu, ram, gpu or everything? 

my fear is that changing pc I don't get anything, just throwing money away!

really stressful and demotivating!!! 😠

thanks in advance for any help!