Bah. Cpu usage is a measurement of time. It's how much time the cores are at an idle state between use. So if the cpu is at 60% usage, 40% of the time the cpu is doing nothing but waiting for instructions.
That's important only for headroom. It means in the next frame there's room for the cpu to add other instructions, like a physX explosion or some Ai computations etc, and not affect fps output. If the cores are reaching 100%, there's no time for anything else, like adding that explosion, so the frame takes far longer to complete. Fps goes in the toilet.
Most commonly found in high-end systems and low-end games like CSGO, where cpu usage will be 40%, but 2 individual cores will be at 100%, because CSGO does not rollover instructions to new threads. It's also common on low-end systems where ppl use low presets to increase fps.
One of the biggest misconceptions about gpus is that they increase fps. They do not. Fps is solely the responsibility of the cpu. It takes all the computations, all the code, all the objects, physX, dimensions, everything and packs it into a frame package and ships that to the gpu. The amount of times the cpu can do that in 1 second is your Frames per Second.
The gpu either lives upto that number or fails. In cpu bound games, the gpu generally has less work, so can maximize fps onscreen upto the limit of what's sent by the cpu. In gpu bound games, it fails and the cpu sends more than the gpu can handle.
With a lesser card like the 1060, replaced by a 3060, the 3060 has better ability to put more frames up onscreen in gpu bound games.
So in CSGO the cpu might send 200fps. At 1080p, that's easy graphics for the 3060, so at medium it puts up 200. At high 200, at ultra you get 200.
But, the 1060 was also strong enough to do the same. So end result is you get no visual gains since both cards were capable of 200fps. Limited by the cpu.
Change that from 1080p to 1440p and now graphics are 1.8x more intense, the 1060 will suffer and at ultra can only put up 100fps, but the 3060 is still strong enough to put up all 200fps. Vast visual difference.
That's why you aren't seeing much of a change. Lower resolution, lower refresh, lower fps and similar results. If you challenge the gpu, by using 4kDSR or upgrading resolution or running highly graphical intensive games, the differences between the 1060 and 3060 will become more obvious.