1440 Gaming PC Recommendations

It's been about a 7 years since I built my last PC. Proud that it has lasted me this long but I think it's time for an upgrade. Currently have a 1070Ti with i7-6700K CPU @ 4.00GHz. I only really play Apex Legends at 1440p and plan to play some Diablo 4 when it releases. For Apex I am trying to get high FPS, I've noticed lately that my frames have been dropping. Not sure if the 1070Ti is just getting old. The monitors I have can be overclocked up to 165Hz and are G-sync compatible. I don't really plan on having to change those out since I've purchased them in the last couple years but if you have some monitor recommendations please don't hesitate to throw them at me. Also, my first PC's motherboard did not have WiFi built in which became a problem recently where I had to buy a WiFi card in order to have my PC in the apartment where I wanted it to. Do these new MoBo with WifI 6 capabilities get strong signal or is that dependent on my router? My PC is only about 20' from the router location.

My budget is about $3,000 so I've put this list together and I'm just wondering if this might even be overkill for one (and soon to be 2) games I play. When I built my first PC I remember just forking out the extra money to get the best stuff available at the time. My main question is just could I slim down anywhere in this build? Power supply? Case? RAM? AIO Cooling?

Thanks in advance. First post.