This is true but the issue is the amount of fake outs we get with deaths in One Piece as well as just how wildly inconsistent people's resistance to attacks can be.
We saw Pell survive a nuke and Pagaya survive a massive thunder from Enel, yet bombs and dynamite have now become incredibly deadly to Pedro and Ashura.
We saw Law survive multiple gunshots and we saw a lot of characters get hit by shigans from CP9, yet Izo here dies by one from CP0.
It's not a bad thing to have sudden, tragic and unsung deaths in a story but with the way the story has worked in the past in makes it extremely hard to tell when characters actually die.
Like seriously to this day we still have people wondering if Vergo is actually dead.
What fake outs?
Please explain - the only "fake outs" we have are:
Pell - which was because when he died 911 happened and Oda didn't want to have his content in any way similar to such a disaster and contemporary to the attack - it can also be explained away in-verse as Pell being an awakened Zoan
Pagaya - Enel's attacks use Volts (which are not lethal) rather than Amps (which are lethal) - there are plenty of other people in Skypiea (Kamakiri, Laki etc) who were not killed by him which proves this is a consistency between real life and One Piece. Volts burn and cause complications to do with the human nervous system but cannot kill you - it is Amps that kill you and Enel appeared to have far less control over the Amps of his charges.
Kin'emon - was not a fakeout, he survived because Law never undid his splitting, which if you go back and check, is actually legit true and it was very clearly a planned plot point to give Kin'emon his moment
Who else isn't dead that should be?
- Surviving gunshots is common and Law is superhuman
- Those attacked by Shigan are superhuman - and also were attacked by CP9 who are far inferior to CP0. We also know that by post-skip standards, Izo is not a relevant character for powerscaling so his death is very believable in that sense
All this tells me is you either don't pay much/enough attention or you're simply lacking a lot of knowledge here and it's the same for anyone else who thinks these deaths are somehow a bad thing.