This just drags out combat. The idea going against a to-hit number is so combat can be resolved without back and forth every attack, especially when there is the GM running all the monsters.
A bit off topic, but I saw a discussion on Discord recently about dedicated healers. Basically complaining that in certain systems, healing is worthless because enemy damage output always outstrips healing in the long run. People try to explain that it's a design choice to stop infinate combat or stop the party from being unkillable, but they don't like that answer.
Similar discussion happened about a dedicated tank. Complaining that only paladins can do it. People try to explain you can go full armour fighter or other builds like a high dodge monk or a high con barbarian. But they aren't "pure" tanks.
It feels like a MMO way of looking at RPGs.
Rant aside, if modifiers are known, it is equally fast for both parties to roll one die and do one simple calculation as it is for one. Stay focused, keep it moving. I'll give you a little room to plan, but just that, a little. Resolve all arithmetic immediately because it is literally elementary school math.
I don't have a problem with modifiers. What I have a problem with is stacking modifiers. Same with multiple die rolls for the same action. On the surface, it's just a few seconds, if that. d20 + 2 + 1 + 1? Easy. d20 + 5 vs d20 + 8. Easy. The problem is these 3 second delays begin to pile up, and before you know it a round of combat is taking 20-40 minutes. Things like turn timers cut down the fun parts of the game to make more room for math, instead of the other way around.
Unpopular opinion, but this is why I loved 5es Advantage/Disadvantage system, and why it's been used in other system despite claims from the grognards that it should just be + or - 4 that stacks or that it dumbs the game down. It's why I like dice pools where you count successes.
I remember playing Knave via VTT, and while my players hated it, I liked it in part because turns were so fast. People kept getting up to take a piss or browse twitter or whatever only to get a bunch of pings telling them to take their turn already. They weren't used to 30-60 second combat rounds.
I never heard this term, but it's the same concept I've used for a while. I've heard of similar concepts. It's one of things players are best off not knowing as it can break the illusion.
"Floating clues" goes by various names but is the investigation version. If the players need to find a receipt from the wax museum on the person, it can be in his jacket pocket, his desk drawer, in the waste paper bin, even in his car glove box. Where ever the PCs search where it makes sense to be.
"Secrets and clues" is the name I've heard given to the plot version. From the lazy DM guide, in prep you lay out the information the PCs need to learn over the adventure, and then have it presented in any way that makes sense. Same with items they need.