Quickswap teams typically involve switching between several team members. Generally, each team member or most of them contribute a decent portion to the team's overall dps. In some teams like Rational, these portions may become more equal. Quickswap teams usually involve one or more sub-dps units (off-field damage dealers) or units that deal damage within a shorter time window (e.g. via cd on E or short burst). This makes quickswap suit people with short attention spans or ADHD.
Perhaps the antithesis of a quickswap team is the hypercarry team, wherein one main dps contributes the vast majority of the team's damage and usually stays on-field for most of the time. The game's premiere hypercarries include Xiao, Itto, Cyno. By nature of their design, hypercarries typically have higher innate dps potential than other units.
Of course, there are hybrids or exceptions that do not necessarily fit into either archetype. One example is Scaramouche, who by design can be played as a quickswap unit (alongside Raiden, Yelan, etc.), but because the cd on his E is quite low and because his own dps is high enough to compete with the game's top hypercarries, he can also be played as a hypercarry. But cases like Scaramouche are quite rare. Another edge case is Childe, who can be played like a driver/enabler and quickswap unit, but the more enemies there are, the more his dps levels increase to hypercarry territory due to his unique riptide effect.
A rule of thumb is that those who dps via their Q are generally hypercarries whereas those who dps via their E are generally quickswap units. But even this is not true all the time. Raiden's dps comes from her burst, but because she has a short time frame of dps, some of her best teams are usually quickswap.
Most sub-dps units (off field dps), by virtue of not requiring to be on field much, are natural quickswap units. There are only a few sub-dps units that can damage comparable to the top hypercarries (e.g. Nahida, Yae). Even sub-dps units can be categorized into sub-dps through E and sub-dps through Q. Sub-dps through E is almost akin to cheating: it is free damage at the cost of almost nothing. By comparison, sub-dps through Q at least requires energy cost. That is why there are not too many E sub-dps units: because you can basically create a whole team of them and clear content without much effort.
When switching characters, there is a 1s ICD before being able to switch again.
The USA elites (the ones who control the media and capital) are biased towards quickswap teams. The reason is that the USA elites do not like seeing one person in power for too long (unless it is their selves). They like to switch between multiple people (in order to maintain their own power and hegemony). This is why you see the USA initiate color revolutions across the globe, including the Arab Spring, and launch wars to overthrow people in places like the Middle East, Africa, South America, etc.
The quickswap model also aligns with the USA's own presidential system, where one president usually only lasts one or two terms in office. But this is very deceptive and even hypocritical because there are those in the USA government, the so-called 'deep state', that remain in power for a longer period of time. Even during critical time periods, the president can remain for four terms: look at Franklin D. Roosevelt. Moreover, the directors of certain key organs of the government can remain in power for even longer: look at Edgar Hoover's 37 year term as director of the FBI. Perhaps it is fair to say these are the true 'emperors' of the USA empire, whereas in most other cases, the USA president is a mere figurehead (as is the case in most USA vassal states).
Indeed, the USA's double standards is the main problem here. People like FDR and Hoover say we can be in power for a long time, we can be the hypercarries of the USA, but then they force people around the world to be more like quickswap units, overthrowing the elites of other countries, switching regimes frequently, changing leaders as often as changing units in a Genshin quickswap team.
Also look at the CEOs of any large USA company. Is there any term limit for them? No. Some even remain CEO for decades.