iserith
Magic Wordsmith
I've watched quite a few games on youtube from different groups. There seems to be two camps.
Those influenced by CRPG gaming tend to group optimize, strategize in combat, and treat each combat like an individual little tactical war game. There's a couple of groups out there I've seen who play D&D this way - unfortunately though one group has given up on 5e and has gone back to streaming pathfinder which is a chore to watch.
I've ran into about 8-10 Kobolds with my Cleric and didn't get hit once. Why - dodge action + high AC. I drew fire while everyone else picked them off from range. That's MMO thinking - I don't care about doing damage or being the 'star', I want our group to win. In MMO's you need to play like this or you simply cannot proceed through to the next boss and get your rewards. It conditions you to think differently.
When we pick characters and builds, we think of "Role that will help the party win" first, "concept" second.
Lots of other groups that I've seen don't really do this kind of thing. They don't focus fire. They don't use the dodge action. They don't utilize cover and pop out and attack. They do what their characters would do, which often leads to some pretty poor tactical decisions. But hey, they seem to be having fun. The EK in your example earlier probably would have lived if he used dodge and his hand crossbow bonus action to attack.
Here's something I think is worth considering:
In a well-designed encounter (or scene of conflict if you will), there should be challenge and difficulty. Many times these concepts are conflated, but they are different. Challenge is when there is a conflict that can go either way - the PCs can win or lose (whatever winning or losing means in context) based on what they choose to do. Difficulty is how hard it is to achieve success. The choices of the PCs in a well-designed challenge can either increase or decrease the difficulty. Naturally, players will want to make solid choices that decrease the difficulty to increase their chances of success and - in a D&D context - will generally cost them the least amount of resources.
However, there is a problem with this: Reducing the difficulty too much can also make the challenge less satisfying, especially if the choices involved in reducing the difficulty are essentially the same from encounter to encounter. So we have these groups of optimizers (a term I don't use pejoratively) that are essentially using the same tactics over and over. They've got particular feats because they feel those are "must-have" choices. The cleric is a bless machine. And so on. The same operating procedure is trotted out every time initiative is rolled. The challenge is subsequently reduced in difficulty and is, as a result, less satisfying.
Because these scenes are less satisfying, the goals of play - having a good time together and creating an exciting, memorable story by playing - are harder to achieve. As a result, the group searches for a solution and settles on getting rid of or changing the feats. That's fine, as far as that goes. Really though, the problem is the players choosing particular procedures for reducing the difficulty to an unsatisfying level. This is like always playing a computer or console game on Easy Mode. Can it be fun? Sure, for a time. But since we know that some measure of difficulty is necessary for a satisfying game experience, it's important to keep this in mind and to temper one's choices so as to more easily achieve the goals of play.