EzekielRaiden
Follower of the Way
Formally speaking, it's more than just that. It's that the Warlock can rest after doing literally anything, whenever they like. A Warlock that spends half or more of the day resting. The examples given were not of single-encounter days, but rather single-combat days where there's 5-7 other, non-combat encounters...and the Warlock rests after literally each and every one of them as well as after the one combat encounter.That's true. But that's also The assumption. The one-combat day assumes that after the combat, another one won't occur until the next day.
Otherwise, that wizard/sorcerer/Paladin will have significantly less resources as well.
Which, again, is the sticking point. Yes, if the Warlock is allowed to short-rest 5-7 times a day, they're going to do quite well, because they may even surpass the Wizard for total spell slots (and massively so if you weight by spell level; e.g. at level 11, admittedly the point at which the rules most favor the Warlock in this comparison, 3*5*6 + 6 = 96 spell levels per day for the constantly-resting Warlock, vs only 4+6+9+12+10+6+6 = 53 spell levels per day for the Wizard, counting Arcane Recovery.) The question is: would DMs let the Warlock constantly rest? My experience, from discussing it with others who DM 5e, is emphatically no. The so-called "Coffeelock" build, which leverages the Warlock's short-rest slots to squeeze out more Sorcery Points for Sorcerer shenanigans, is met with dramatic opposition by most DMs, to the point that it makes them want to ban multiclassing entirely. It is, if anything, even more disliked than the "Hexblade dip," which is already heavily disliked for being "cheesy" etc.
So...yeah. People complain about the relative power of the Warlock in part because no, DMs do not appear to rule in such a way that the Warlock is favored. They instead tend to rule, and run games, in such a way that Warlocks (and other SR-based classes like Battle Master Fighters) are weakened and not improved. And you would be right to say, "Well if people have a problem with games being run that way, why don't they do something?" There's just not a lot that can be done, because the only solution is to choose to become a DM yourself and run it differently...and that's an awful lot of responsibility to take on solely because you want more fairness in rulings toward one particular class. Easier to just play some other class that isn't subject to such issues (or, more realistically, to just complain about the issue online, consequence-free, for basically zero effort.)