In my view it's always going to be quite tricky to give encounter-level guidelines for a game that uses "adventuring-day" level resource management.
Classic D&D (OD&D, B/X, Gygax's AD&D) deals with this by encouraging a play approach where players make decisions about what combats/skirmishes they take on. This is facilitated by a convention that generally (not necessarily always) GMs present encounters to players in one of two ways: when the players have their PCs open doors; or when the wandering monster die comes up 1 (or 6, depending on one's rolling convention).
2nd ed AD&D deals with the overarching issue in a different way. It encourages the GM to more actively manage the presentation of encounters to the players (whether under the notion of "the story" or "the living, breathing world"). And at the same time it encourage the GM to fudge, or otherwise set aside the action resolution rules, to make things work out as desired.
I don't have a good handle on 3E, but I suspect in practice it relied quite a bit on the 2nd ed approach.
4e avoids the issue because it maps encounter-level guidelines onto a framework of predominantly (not entirely) encounter-level resource management. And my experience is that its guidelines work.
5e has the issue (because of its resource management structure) and doesn't promote the classic approach to dealing with it. It doesn't seem to fully embrace the 2nd ed AD&D approach either. Its approach seems to be to set encounter difficulty guidelines at a sufficiently generous (to the players) level that even a party that has suffered quite a bit of attrition from prior encounters is likely to be able to handle what is thrown at it.
If those encounter difficulties are stepped up, then I think that takes the game back into the 2nd ed AD&D approach.