Well, the manga has made the point that what influences the strength behind conditions and whatnot in the individual's personality and psychology. Nen alone can't make the objective assessment that gon is not loosing much anyway at that point. What was important was what was going on in gon's head. Which at the time was kite and his desire to avenge him. Its the same thing for kurapica and his chain jail. Its because he specifically wants to target the spiders that his chain is so effective against them. Someone else doing the same thing would not necessarily mean he can restrain the spiders as kurapica does.There's no indication conjured items have any better physical quality than normal stuff. Beyond Netero was shown handcuffed by what's presumably a real handcuff, and he's likely the strongest human in the entire series by a significant advantage. Ignoring special property that randomly ignores the 'limit of human' like how Shizuku can suck things up to another dimension that she doesn't even know about, conjured items are quite worthless compared to their real counterparts, which is why you randomly have conjured items that can do stuff that are quite beyond human capability, but only if Togashi decided to give you such a bailout.
For the conditions, just because Togashi has a way of making bogus conditions sound like it's very hard doesn't mean one can't apply some critical thinking. Giving up your life is not a serious condition when facing a guy who has 100% chance of killing you. If what Gon does is actually perfectly normal then you'd just have guys randomly turn 10 times stronger right before they die because after all if you're going to die you might as well mortgage whatever future you could've had and it's not going to get any worse, so for example when Hisoka fought Kastro, Kastro no longer had enough aura to use another clone, but he should be like: "I'll never use aura again so I need about 10X of my current power to defeat Hisoka now", and then since Hisoka technically had no arms left at that time to defend against even a normal attack he'd be forced to also use a "never use aura again" power and then Hisoka would be done. Netero's final attack basically used up his remaining life force and all it did was made Meryem more bruised than usual, and the difference between Netero and Meryem is considerably less than the difference between Gon and Pitou.
Yes Gon has super potential so you can handwave some of that stuff, but the notion that he had to give up a lot is nonsense. He would have died with 100% certainty if he didn't get his bailout power. Whatever aftereffect you may have to suffer is still better than dying outright. And no there is no such thing as 'fate worse than death', because otherwise anyone would just ask for super power bailout for suffering a 'fate worse than death' and it'd be the complete norm to see random newbies completely destroy the top 5 users because they're willing to take a 'fate worse than death' condition. Sacrificing your life should roughly be the difference between bruised and more bruised (the amount of damage Meryem took from Netero's attacks), and that was from one of the most powerful characters in the series.
Also, gon didn't just sacrifice his life. Surely that was a part of it but there is also the consideration that gon as a whole was said to bet his entire potential which presumably exceeds netero's. Netero as an old man probably would not have had that potential thing to gamble as gon did. We can also make the point that for gon the whole thing was ultimately far more personal than for netero. Netero just wanted a good fight, one to wage his life on, but still only a good fight. Gon presumably had much stronger emotions at play.