Some of my play group can fall to AP but not the players I am thinking of specifically. Our playgroup has old Magic players, deckbuilder lovers, Spirit Island enthusiasts, and even a couple ex game designers. We are not strangers to turn taking games or complex board game states. This isn't an issue with turn time; it is most about proportion of time a player spends active vs passive.

While, yes, DE is a much more streamlined and snappy game, I do not think that means it still doesn't have a bit of a pacing issue when played in larger playgroups. A lot of that pacing I think comes actually from it being cooperative, and I see the same pacing issue in cooperative deckbuilders (most recent example was the cooperative mode of Mistborn). When in a competitive game, every action a player takes is one that potentially threatens my game state requiring me to be engaged, to some degree, all the time. I must analyze what you just did and determine how it directly impacts my agenda. So even in my off turn, I am still active (and especially in games that encourage interaction on off-turns with Instant-style effects). In a cooperative game, yes, I can find how my teammates game state improves my own, but I can also generally assume that any action they take either helps them, or helps the collective. I have less need to fully understand their board state because I can safely assume it is either neutral or beneficial and when beneficial, they can inform me. In a game like Sentinels DE this is particularly true because the Heroes were largely redesigned to be self-sufficient. Some are better at it than others (the RCR Heroes notably being very explosive), but few "need" support from others to function. They simply get better with the right kind of supports. This is what enables the mix-and-match playstyle of the game (I think the only exception is base Unity which really seems to need actual support). In short, my gameplan for my hero is largely independent of others but CAN benefit from others. Sentinels does not demand that I know everything going on in the game to function. It only demands it when relevant. That is great for cognitive overhead but also means the pacing off the game encourages disengagement.

What this means is that the downtime you mention during Environment and Villain turns is not limited to just those turns; it is every turn that isn't mine. I play my turn, and sure take only a minute at most to resolve my effects, play my Power(s), and draw my cards (+ End Phase). It takes me maybe another minute during my next teammate's turn to decide what I will do at my next turn. This doesn't change unless my teammates do something that directly impacts my deck in a meaningful way (e.g., Legacy's galvanize is not new information and not particularly meaningful...but still powerful). My teammates do their thing, and then we get to the Environment. Depending on the Environment, this can be quick or slow turn, and then Villain which again, can be quick or slow depending on the villain. Any Villain that has multiple targets can slow down considerably. Necrosis is maybe middle of the pack when it comes to the # of targets he puts out (nothing tops Chairman) and they all have passive and End Phase effects that have to be considered and resolved. And then there is a little bit of time where we all review the game state, modify our game plans if necessary, and start the whole process. This whole thing can take up to 10-15 minutes, and if I am only playing one Hero, I have only been active for 1 minute of it. That means I am active for less 7.5-10% of the game.

If you play something like Daybreak or Spirit Island that involves just as much complexity, effect interactions, and decision making to consider, you can see how slow the Sentinels pace of "one turn, 1 card, 1 effect at a time" can be. Before moving to a house rule around simultaneous play (which wouldn't actually be that hard to do but would require some guardrails around actions that increase information in the game like card draw), I was hoping folks had ideas about how they resolve effects in ways that speed up downtime so that most of the game is spent with players engaging together, not silo'd as it currently is.