Great points! As mentioned above, in my own campaign, assassins were thwarted by not letting them abuse the body.
I freely acknowledge that I'm stretching the definition of 'taking it to its logical conclusion'.
Like most points in the discussion, it's not every campaign - these are outliers, that's for sure - but look at it this way:
LG Warrior gawd genuinely wants his people to triumph on the mortal plane - why let his best asset 'retire' to the afterlife? He'll send him back in like an over leveled pokemon again and again.
Old age? Potion of Longevity. Main ingredient is Elf Blood. With modern D&D being a Flinstones setting* more often than not, how hard is it to have a blood drive?
Raise Dead is cheap, big-picture wise. A kingdom would scrape the resources together and have a suitable cleric nearby like a defibrillator.
All of these things are like the Transporter in TOS - its in there to shortcut a problem with the style of stories they wanted to tell, but creates lots of strange ripples down the line.
Edit: The above is why Demon and Devil worshipers in my campaign are at Warlocks (no clerics) the false gawd fire cult are sorcerers showing off, and the atheistic/agnostic/antideist High Elves have spawned the Warforged, Clone Spell, and Lichdom in my campaign (mind you, they were Melnibonean-lite back in the day)
*Flinstones setting - It's exactly like modern day but with alternate tech.