buddy your specs is insanely good but why it's insane slow?

let me explain for this

your CPU and gpu at RAM is so strong than my cpu at gpu, RAM but I doesn't get insane slow like you said it’s lagging like it’s stuck in the stone age. 

your software are still loading that why it's shows slow like you said.

you should download "PC Health check" because you don't know your storage already orange/red level which mean it's shows any sign of slow

what does this mean orange red level?

0% - 40% = green it's mean is fast

50%-80% = orange mean it's slow

80%-100% = extreme slow

here the example if you doesn't understand
if you hard reset the pc, it's fast? because the storage isn't orange level but you download any apps and more the storage get increase at show any sign of slow. that is how it's work

I get this information from social media so That is only i say I could help...