Many prefer the first part of Death Note to the second part and that's fine, people have different preferences. But I cannot stand the claim that Ohba and Obata only extended the run because it was doing so well that Shounen Jump pressured them to do it for more money.
Death Note follows the classic "Rise and Fall" tragedy. The first part is Kira's rise to power, the second is his fall from grace caused by hamartia. Which in Light's case is literally hubris - the most deadly and dramatic of them all.
If Death Note had ended with L's death, it would have been like:
If Macbeth ends when Macbeth becomes King of Scotland, and not when Macduff kills him
If the myth of Icarus ends when Icarus soars high above the clouds and not when he falls into the ocean
If The Rise and Fall of Ziggy Stardust and the Spiders from Mars ends with Starman and not Rock 'n' Roll Su*cide
I say all that to say that Death Note must not, in any case, end unless Light/Kira has been sufficiently brought down.
Most adaptations try to reconcile with this while neglecting the second half. Like the first series of Japanese live action which gives L the victory a few minutes after he feigns death. Or the Netflix live action (forgive me for evoking its name) where Light ends up confessing all his crimes to his father on a hospital bed.
But this is not a "Rise and Fall" or at least not a good one. It lacks the dramatic impact of watching a man climb to power then slowly lose control of himself and everything he works for. The reason Death Note's second part is so satisfying is because of Light's gradual descent while still clawing desperately to hold onto his peak. Like if Icarus while falling still tries to flap his broken wings to get closer to the Sun once more.
There is no catharsis in a quick fix. Live action Light is simply outplayed for a moment, he is not brought down, not defeated the way manga/anime Light is.
Which is why despite all its MASSIVE flaws, I have to commend the 2015 drama series because at least they TRIED to be faithful to the structure of the original story. It's not that it's the only non-anime adaptation that features Near and Mello (debatable), but it's the only one that gives Light time to fall. I'll take it.
(But lowkey Rise and Fall stories work best when pride is a central theme and a primary characteristic. But TV Light was not introduced with that trait so when he starts acting like OG Light there's a real disconnect but it's fine, it's fine, really)
