No, not every one - but I run a lot of combats where the heroes of the tale feel heroic and that they are not at risk of dying. A massively underutilized and misunderstood opportunity for improvement with a lot of DMs is the misperception that encounters must meaningfully threaten the lives of PCs to be enjoyable or contribute to the quality of the game.
So, the 7th level party is traveling through the Goblin Forest and encounters Goblin Warband. The appropriate establishing and reaction rolls are made, and the goblins attack. The gobs have no chance outside of really, really bad rolling on the part of the players. The fight is not part of the main storyline or anything. OK.
HOWEVER, when the PCs encounter the Goblin Warband the goblins are attacking a caravan of travelers from the town ahead. When the PCs make their presence known, the people beg for protection and help. The goblins are not going to attack the heroes. They're trying to drag off the people. The PCs will never be in jeopardy in this fight ... but they can still lose out if the goblins are allowed to escape with the people. If the PCs save the travelers they can give information about the upcoming town. If the goblins escape with a captive and the PCs recover them they might discover additional treasure in the goblin base. A few days after they arrive in town, word of their heroic protection of the travelers may reach back to the town and a wealthy benefactor may approach them. On the other hand, if they let the people be taken by the goblins ... or do not utilize resources to do it fast enough and some people die or are lost... their lack of concern may be the reputation that reaches the ears of others. The local rangers might come across the scene and determine the PCs were there during the combat and failed to help - and may raise that to the government, the public, or those that the PCs wish to engage.
In my experience, every encounter should have a way to win, and a way to lose. However, only a small portion of those combats should be ones where losing means death. If every combat is a battle for survival you get three problems:
1.) If there is a meaningful risk of death in every combat, probability indicates you will get TPKs more often than most people consider acceptable fun,
2.) It doesn't feel heroic to constantly feel threatened and unsure during every combat because every time you randomly run into something it is a deadly encounter ... you feel more like a victim than a hero, and
3.) Your world logic tends to be destroyed pretty quickly when threats capable of killing 11th level PCs are running around next to every town they encounter. If a small army of evil and destructive giants is next to a town, that town should be rubble.
So, when do I wave away combats? When I want to remind the PCs that they are awesome and powerful, primarily. It is entirely possible that 6 goblins will attack a party of 5 11th level adventurers as they leave town. If we determine that makes sense and happens, I won't roll a combat. I'll figure out how the combat would have opened and then ask them what they want to do. Kill them? Capture them? Use magic to control them? Scare them to drive them away from town? I won't roll out the combat. I may ask someone to roll a single die and use the result to say how well they execute their path ... but I won't have the combat roll out.
Why is this a good idea? It reinforces for the players that their PCs are above these types of encounters being a threat to them. I could have given the goblins a goal like I describe above and allowed the PCs to deal with trying to prevent that goal from taking place... but I can also just use it to reinforce the idea that these PCs are not low level or medium level anymore ... they're in that realm where they are powerful and important. This approach conveys that message.
So all in all - Yes, I sometimes bypass combats ... but it is rare and strategic when I do it. Beyond that, I am primarily giving the PCs something to accomplish outside of mere survival when I put them in most combats.
