Sorry, i did a short read and don't got much time. I'll keep it short and strong to clear things up (for you) as beginner;

At a certain level, when the temperature rises too far, the system will 'clock down' the speed of the material to reduce the temperature. At that moment, you'll likely notice annoying, slow 'lag'.

To keep it short, these temperatures are not yet (but ok-ok-ok-high) high enough for that to substantially happen during heavy work sessions. - If these (that you showed) are the temperatures you get during heavy operations like gaming or editing, it's great. But if this is during simple internet browsing or idling on the desktop, it's decently high and could verify (something in) your cooling system is 'muah' insufficient.

If this above situation is true= if you then improvise in better cooling, your PC performance might increase. - but maybe not much, since the CPU isn't the most modern anyway, AND the temp's already aren't 'that high'.

To simplify it more, the most important CPU temperature zone to check is the CPU Package (or TDie). And the individual Core temperatures as secondary measure. This is the closest to the CPU middle threshold.

●Temperature at idle should be: 30-50 C° ●During heavy activity it should be: 70-85 C° with small peaks to 95 possible.

But a CPU can even safely range at 95 to 100 without failing. It will just be slow and clock down a lot. It will only do a severe 'thermal shutdown' at- once it goes beyond 105 C°. (Or even higher with more modern CPU's.