I've recommendations to have initiative predetermined for all the encounters, which seems strange to me, because how do I know what all the encounters will be.
I've seen recommendations where the players stick to one initiative order, either rolled at the beginning of the session or the just select their order. But I feel being stuck going in the same order every combat would get old fast.
Lindybeige has a video trashing D&D initiative (though he's not a fan of the D&D system in general). He argues against basing initiative on dexterity. He argues that initiative is based on experience and skill, not how dextrous you are and suggests that your initiative shold increase with your level. But his biggest complaint is not the pause to roll inititiative or the manner initiative is determined, but rather he dislikes the whole concept of taking turns in combat. His beef with initiative is that it is unrealistic and it slows everything done. He wants initiative to be completely free form and uses Runequest as an example.
In the version of Runequest that I played in the old days, everybody just said what they were going to do and the referee said "okay, and now this happens and I'm going to go to you. And, if someone charges at you, you just retreat from them, because, well, you would, wouldn't you? There is no moment of your turn starts now.
As much as I like his videos, I disagree with him here.
Lloyd (Lindeybeige's actual name) is envisioning this:
https://youtu.be/tOUksDJCijw?t=1629 (27:09 to, oh, about 29:12, but if you can stop watching, you are dead inside)
But that, of course, is not what is happening. Everything is happening fast but we are slowing down to fight-time. And Lloyd's alternative isn't satisfying for me. It is mostly narrative and up to the DM. You are taking things out of the hands of the players. In some games, like, oh, InSPECTREs, a highly narrative approach makes sense. There are radically different mechanics in that game to support that. Initiative is a simple concept that helps keep combat manageable.
And if you are going to attack the initiative system based on verisimilitude, is that really the place to start? How about falling damage, swimming in plate mail, and so forth. When I have played with DM who add lots of home rules to increase versimilitude, it always seemed to bog down the game and didn't really add to the fun.
As for creating a break in the game, right before combat, well, yes! I've always found it adds to the excitement. You are switching into combat mode. Rolling for initiative is a tradition and ritual in the game I cherish and I would be disappointed to have it taken out of the game.
As I DM, I have sped up the process by using the "initiative score" variant discussed in the DMG (Chapter 9, under Combat Options).
Initiative Score
With this optional rule, creature don’t roll initiative at the start of combat. Instead, each creature has an initiative score, which is a passive Dexterity check: 10 + Dexterity modifier.
By cutting down on die rolls, math done on the fly, and the process of asking for and recording totals, you can speed your game up considerably—at the cost of an initiative order that is often predictable.
Players still roll and I may still roll for named NPCs and more power boss monsters. Since I started running Curse of Strahd, I went back to just tracking initiative on a piece of paper so having, say, all Zombies go at the same time in initiative order and not having to roll for them, speeds things up.
In my prior campaign, I used Hero Lab's tactical console, so rolling initiative for even a large number of creatures was simple. If you let it role for the players you can have new initiative order every round pretty easily. But I still found it more complex to have this zombie go, then that player, then a different zombie, etc., even with software help, then just having the zombies go together on same initiative order.