Any budget?

You can still keep your CPU and Mobo, but the RAM needs to be upgraded to dual channel + better clock speeds (I'm guessing currently, it's at 2400Mhz since its DDR). Something along the lines of 2 x 8GB 3200Mhz C16 would give a real good bump to your performance.

SSD upgrade to a DRAM model (e.g., Crucial MX500).

PSU really needs to be upgraded to at least 550W (Gold), or get a larger 750W (Bronze or White).

Graphic card I'm not too sure, but a GTX 1660 Super will be much better performance:watts gain.

Yes, if you manage to find a second hand RTX 2060, it'll be better