I have had type 1 for 14 years and only experience tiredness when my BG is too high or too low.
I managed my diabetes through basal bolus injections for 12 years and avoided high and low BG most of the time so rarely felt tired due to diabetes.
The value of a pump is that it gives you to adjust your basal dose. This may be, for example, because you need more insulin at the start of the day or less insulin during exercise.
I have had my pump for two years and found it incredibly useful for exercise and been able to noticeably improve.
However, it is not a silver bullet: it took some time to get my basal levels correct, it requires close carb counting, it requires set changes (including inserting the cannula) every 2 or 3 days, it is difficult to hide so my diabetes is "on show" most of the time ...