Yes and no. Dashing gives you a larger time window to avoid incoming shots than if you had to reverse strafing directions. But to compensate for it, more enemies at once will throw projectiles at you (where Doom 2016 had that token system that limited how many enemies could attack you at once, but in Eternal that seems less of a problem), and most projectiles in general are faster and have more leading applied to them. Especially fodder enemies will keep pelting you, but as fodder enemies deal less damage in Eternal than in 2016 they don't become an uneven threat (unlike Imps in 2016 who were the most threatening enemies in Nightmare with their 45DMG fireballs). Another thing to consider is that more enemies fire projectiles in bursts. The Arachnotron will fire projectiles in a sweeping pattern, where the first shots underlead to catch you if you try to immediately reverse directions, but the last shots will overlead to catch you if you keep dashing in one direction. So the Gargoyle, Soldiers, Cacodemon, (Cyber-)Mancubus, Carcass, Whiplash, Tyrant and Doom Hunter all possess attacks like these where their burst lasts long enough so that if you dash too quickly (or not at all), it will be on cooldown when you need it the most. Dashing makes it easier to deal against single projectiles because you can usually dash left/right and avoid it just fine (which is why Eternal throws greater volumes of them at you), but dashing against projectile bursts is like having to deal with melee tracking in Dark Souls; you need to time that shit. In fact, charging Pinkies in Eternal will track you if you dash too early.
Another reason why I believe dashing is a net positive is because it makes dealing with enemy melee attacks consistent. The problem with melee attacks in FPS is that as long as you move faster than the enemy, you can always avoid their melee attacks by simply backpedaling or circlestrafing. So it's up to the level design to restrict the space you can backpedal in. Only this won't work in Eternal's open circular arenas especially now that you have a grappling hook to move about even faster, so a different approach is required. Dealing with Hell Knights and Barons in 2016 had this problem where sometimes they would do their leaping ground pound attack at a position that you can't realistically move away from fast enough with your movement speed, meaning taking damage was inevitable. As increasing the movement speed only enables more backpedaling, having a "normal" speed but being able to immediately dash across large distances allows dealing with inevitable melee attacks to be a matter of timing your dash. Which is especially useful against enemies like the Dread Knight whose ground pound has a massive AoE.
Uhh, what?
Default dash cooldown (assuming you take the dash cooldown reducer because of course you take it, its the best upgrade in the game) is 0.75s. There is no instance in which dash ends up "on cooldown" and unable to be used vs. whatever, unless you fuck up and double dash. And about half this time is spent dashing to begin with, so really its more like a 0.375s cooldown.
I'm not sure you understand the concept of leading. Shots can't have "more leading". Shots in both games have infinite leading. If you are moving at 4 m/s and the shot would take 3s to hit you, the enemy always aims 12 meters ahead of your current position in both games. The difference is that in Doom 2016 you need to specifically recognize this and slow down, while in DoomE your velocity is rapidly changing such that you are almost never at the spot the projectile lands.
While I haven't 100% tested every enemy in the game I can confidentally state that the vast majority of enemies never intentionally overlead or underlead their target. They always lead by precisely your current velocity times the projectile travel time. e.g.:
Mancubus fires 2 shots and you don't dash at all. Both his shots absolutely 100% hit you exactly, because he knows exactly where you will be and how much to lead you by.
Mancubus fires 2 shots, you are dashing the instant he locks on for shot 1 and not during shot 2. Shot 1 massively overleads you, Shot 2 massively underleads you.
Mancubus firse 2 shots, you are not dashing in instant he locks on for shot 1 and are dashing during shot 2. Shot 1 massively underleads you, shot 2 massively overleads you.
(obviously, if he's using his attack that spawns a pool effect and happens to overshoot you due to timing it does become a hazard that you need to avoid or take some damage dashing, but the point is he won't actually hit you).
Melee attacks don't change this. If you varied your velocity in 2016 and/or circle strafed (at a fairly precise distance) you could consistently dodge melee attacks. You had to recognize the point in the melee leap animation where the enemy was locked on and change your velocity to avoid their target. You could 100% dodge Hell knights endlessly in a completely flat area with just WASD, I just loaded up 2016 and did this for several minutes to be sure. There are exactly zero instances of undodgable Hell Knight attacks. This is actually Dark Souls like, needing to watch the enemy and respond exactly after the moment their ability to track you ends (also git gud). In Eternal you don't need to do this, because 0.75s dash recharge means you automatically dodge in time.
Brainless dashing does not work on nightmare, and that is why it doesn't trivialize combat in Doom Eternal.
You have to time it and also consider your position when using it in Doom Eternal. That is the difference to
Shadow Warrior 2, there you can circle strafe dash in the same manner nonstop and it works almost all the time.
I literally beat ultra nightmare rhythmically pounding shift every 0.75s. It absolutely works and trivializes combat assuming you move in a stable loop. Dashing in Shadow Warrior 2 is exactly the same as Doom Eternal except that Eternal punishes you with a 2x longer dash cooldown if you panic and dash a 2nd time too early.
