. The book also claims 3.5 and 4E failed to find new players (context in numbers that mattered).
And $$$ that mattered, 3.5 being shoved out to move books for new-corporate-master Hasbro, and when that wasn't enough, 4e was sold to the suits as having MMO (100mill/year) income potential, though it was only set a goal of half that to succeed.
But, while 3.5 (too focused on selling to hard-core sysyem-masters) & 4e (hampered by the controversy of the edition war) couldn't bring the new players and $$$, 5e finally did (the players, obviously, and I assume it's had a 50+ million year).
5e didn't get those new players by acceding to the prejudices of old players nor by making it so clear & easy as would be accessible to new players, but by walking a tightrope between the two.
Somewhat disingenuous, there was the cure spells and 3E had a level 3 sleep spell with a higher HD cap.
Sure, the 3e Codzilla when not breathing radioactive fire, had a healing spell at every level that it could spontaneously burn prepped spells to cast, so, had the healing burden not been lifted by the WoCLW, could theoretically have ended up looking like poor Robere in my hypothetical real treadmill. I'd also consider the old Death Spell an upgraded Sleep, because the mechanics are similar, and 3e had Heighten so you /could/ cast a favorite low-level save spell forever, if you wanted.
But you're getting your hackles up in defense against a positive.
It's a good thing that, in NO edition of D&D did a wizard ever find himself with no choice but to reprise their 1st-level thing overandover his whole career (it's a less good thing that not all other classes could say the same in every edition).
To be clear, in NO edition of D&D, could you have a treadmill going like the one in my example - where the PCs stay the low-level erandboys for the town's leaders from 1st through 9th level, performing the same tasks using the same abilities, that increase only in nominal levels & bonuses, never net effectiveness, because they never meet a single creature, not even a peasant, that's lower level than themselves.
4E was a literal treadmill
You've got litteral and figurative mixed up, there- seems super-common these days. 4e is notorious for the figurative appearance of a treadmill, an illusion created by it's consistent/balanced formulae for mechanical progression and encounter design.
That's what pemerton & I were discussing.