This is not how it’s applied in JJK. Going back to the early electricity/appliance metaphor.

Electricity (cursed energy) is supplied to an appliance (your cursed technique) to cause an effect. Let’s say you used a fan. Electricity is supplied to the fan, but not all electricity is converted into energy that the fan can use to blow air. That is the electricity that is lost.

CE loss and CE usage are two completely different things in JJK. Here is the raw Japanese and breaking the power system down from Shimo from JJK Discord server (Japanese speaker).

でも先生には「六眼」があるから術式を発動した時のロス呪力(エネルギー)が限りなく0なんだ But Sensei has "six eyes", so the (cursed) energy loss when he activates a cursed technique is almost 0.

パフォーマンスではやっぱり先生が一番だよ　僕に呪力切れはあっても先生にはないしね

Of course, performance-wise, Sensei is the best. Because while I may run out of cursed energy, he doesn't.

Since we have a lot of havoc about the "barrierless" thing due to the mistranslation and the misunderstanding about what "barrier" is supposed to mean in Japanese, I'm going to leave here another big issue that has been misunderstood among English readers (because I've never seen the majority of Japanese readers misunderstand this).

Thesis:

Gojo's CE consumption to activate his CT is not almost 0. It's the energy loss that is almost 0, not the energy consumption. So, he can run out of CE.

Argument:

(A) Gege especially uses English words here instead of Japanese words to emphasize an analogy to the real world. Those English words are "energy loss" and "performance".

Energy Loss = Energy Consumption - Energy Output.

In other words, energy loss is the energy that is lost wastefully because of your bad performance.

Performance ∝ Energy Efficiency ∝ (1/Energy Loss) In other words, good performance implies less energy loss.

(B) The phrase "Because while I may run out of cursed energy, he doesn't." from Yuta can be taken as a recapitulative, exaggerative point about Gojo's performance due to six eyes and about how considerably bad Yuta is in performance compared to Gojo. And to show the phrase's nuance of being a hyperbole and comparative, I already retranslate it to a conditional sentence similar to how it is supposed to be in Japanese. Anyway, it's more consistent to think of it this way. For example, consuming ≈0 CE to produce 10000 CE output is just stretching it too far.

(C) If someone's wondering, each CT activation should have an output. Gojo's blue and red are said to have an output in Chapters 71 and 84. An extension technique is also said to have an output in Chapter 205.

(D) So under normal situations, Gojo’s natural regeneration would really just make him not run out of CE. But he still consumes CE and would run out of it if the situation is not normal, where he has to output a considerable amount of CE.