In fact, there is a difference between paradigm 3.x and 5
After a little research, I came to the conclusion that the role of the rules in 3.5e and 5e differs:
The 3.5e rules serve as a rigid framework, which explicitly states, what mechanics we should use and when
The 5e rules are more like a set of tools, where choosing the right tool is a
subject to the discretion of the DM
An example: how skill checks are supposed to be performed in 3.x
Let's look at the skills, for example. Edition 3.5 part of the concept "the character uses a skill":
When your character uses a skill, you do a skill check to see how well he does it.
Pioneer Define this even more strictly, explicitly describing when "you should do a skill check":
When your character uses a skill, success is not guaranteed. To determine success, every time you try to use a skill, you must do a skill check.
Then, the player says "I use my search skill", for example. Then you have to throw away what the rules of the game want you to do. Then you get a particular result from the list prewritten in the rules. Then, use this ability again (and roll once more) because circumstances changed (he moved 10 feet). This could lead to a large number of unnecessary dice rolls.
This is not how the skills work in the 5th edition
See also Can players declare that they are doing a specific skill check?
The latest edition completely eliminates "skill checks." It wasn't just about changing the name from "skill verification" to "skill verification with a proficiency bonus", it's actually a new approach (an old one, in fact, that's how the rules were used in edition 2 .x): The DM uses a skill check (or other dice mechanics) when they think it is necessary:
When the result is uncertain, the dice determine the results.
The chapter "How to play" describes the process of the game in three steps and does not even mention any mechanics. Instead, players are supposed to describe what their character does in the game world. DMG says the game can be played without dice (the only exception is combat), if the DM believes there was no uncertainty to determine, as stated in "The Role of Dice":
The DM asks for a skill check when a character or monster attempts an action (other than an attack) that has the possibility of failing. When the result is uncertain, the dice determine the results.
The rules use words "might" or "can" in most cases with respect to controls that are carried out out of combat:
the DM could request a verification of Wisdom (Animal Handling)
The fifth edition enables the DM in ways that the third, 3.5 and fourth did not. While the zero rule has always been applied, the fifth edition chooses not to explicitly code many things. DMG addresses this at the beginning of the first chapter:
The rules serve you, not the other way around
Jeremy Crawford, the main designers of the game, supports this idea in several interviews (for example, this Dragon Talk around 45:15).
"… we try to make each piece of the game feel like a tool that players and DM can collect and use with consistency"