Also, I see the wizard brought up often and I believe that I may have mentioned them as well, but upon reflection I think the wizard is irrelevant.
The wizard isn't a warlock replacement or vice-versa. Their playstyles and approaches to adventures are too different to be properly compared.
Even a warlock can be completely different considering their decision points. I have no problem creating a warlock with a focus only on combat while another can be purely focused on exploration and another purely social. And I can mix in-between. Heck, even combat-focused Warlocks can vary considerably.
A wizard, no matter what they choose, is best as a generalist. No matter how specialized they try to be, they either hurt their own strengths or become generalists anyways.
So in a one-combat day, a wizard may or may not have the necessary spells to decimate the encounter, but a combat-focused warlock is more reliable when the wizard doesn't have an answer, quite like a martial.
In contrast, a wizard may or may not have the necessary slots to solve an out-of-combat encounter, but a utility warlock can either do it more efficiently at-will, like using Disguise Self or Levitate, or do things a wizard couldn't possibly do like Gaze of Two Minds or summon Imps/Faeries/Psuedodragons as familiars.
So my point is: even on those days, a warlock is stronger with less combat encounters rather than more even without their rest patterns because even if they can't guarantee their short rests, they can guarantee they'll be in situations where their at-will utility can be useful.