I'm not sure why you'd be disappointed, those temps aren't very high for any cpu. That said it's too hard to say and almost impossible to make any determination about temps being good or bad under fluctuating usage. Temps change with use, use changes with the applications all throughout the task. It's best to develop a baseline of temps using min (idle) and max (full use). Anything in between doesn't matter as much and will fluctuate with use. There's no measurement for 'semi busy'.
Consider running prime95 or other stress tests to get an idea of what max temps are under full load. That's the bigger concern since that's when the cpu is most likely going to overheat/throttle and shows what the cooler is capable of. All cars are the same speed at idle, similar with cpu's. Unless you have a really poorly mounted cooler the idle temps aren't nearly as important. Idle is with the pc sitting and left alone for roughly 5min or so, no interaction, no antivirus scans or updates or anything else going on. Cpu usage should be around 1-2% or less. (It can be impossible to eliminate all background tasks totally).
Most testing for cpu temps and cooler performance is done around 22c, what many consider 'normal' room temp. Ambient room temps can change with seasons and location, if you live in a hotter climate and it's summer your ambient room temps may be closer to 30c. As ambient room temps rise so does cpu temperature. You can't cool a cpu below ambient with an air or aio cooler so ambient is your resting temp before the pc is even powered on. At 30c (hotter room temp) your cpu and air in the case tasked with cooling it is already 8-10c hotter. Not saying your room is hot or not, just to be aware it has an impact.
If someone else with that cpu and that cooler are only reaching 65 tops at load under a full stress test, you may not achieve the same if your room isn't as cool as theirs. If your case and airflow isn't the same as theirs and so on. Minimal differences are normal. When it's time to be concerned or worried about a problem is if most everyone else's cpu is topping out at 65c under stress (as an example) and yours is 80c or 85c.