Level 1: Less reps per/s but for longer time. Infinitely in a surplus situation.
Level 5: More rep/s, but for less time. Not infinite.
A small armor repairer at level 5 is not some over the top drastic improvement over Level 1. With an enduring module the difference is only 3.7 HP/s. Something like 6 HP/s damage over the level 1 skill is not going to be negated by the level 5 skill. At both levels incoming DPS is greater. The problem lies in the capacitor. If keeping the rep running at level 1 is slow enough cap drain to last to a point where you can remove enough DPS to recover, it can outperform level 5. If the capacitor is emptied due to 59s less cap time, the extra HP/s of Level 5 doesn’t matter as you have zero reps once it fails. You’re not going to be able to recover those lost HPs. When you turn it off you’ll loss HPs faster for the missed cycle and you will not be able to recover them under a HP/s deficit. The idea that it’s humanly possible to pulse the module as to precisely match the level 1 GJ/s is ludicrous. Any such attempt will lead to sub level 1 performance.
It’s a marathon, not a sprint.
If you think it’s okay that in some niche situation level 1 would work out better, that’s cool. I personally happen to think this should never be the case in a skill you have to invest into and if you disagree or simply don’t care that’s your prerogative. But to say that it’s impossible for a level 1 to ever be a better option than level 5 is another story.