I often see players switching builds/characters like crazy in a full clear pug, always trying to bring BiS dps build for each boss. So, in the hopes its not just plain obstinacy, here's a few points to consider when you've been in the same habit.
Relogging takes time. If you dont have a ssd, it takes even more time. If you havent your character parked and raid-ready (including food!) in raid lobby, it gets to unbearably long wait time.
The net gain from all dps switching to BiS dps builds is at the most 2-3 minutes killtime. If you already take longer than that switching characters, your switching around dps is a hinderance.
If not all dps switch to BiS - and lets be real, thats more the reality in pug runs - then that time gain is even lower. If those switching to BiS only can reach 80% dps benchmark of the build... then on all bosses except largos and dhuum, its already worse to even consider switching.
I quite often see players relogging between escort and KC, then relog again after TC and before Xera. Thats just unecessary downtime. Theres times and bosses where relogging is possible and helps with clearing the raid faster. For example, before starting w1, w3 or w6, switching to a power dps class. W1 and W3 you can just stay on that power dps class and all is well, w6 offers enough relog opportunities after CA and Largos.
But just following SCs BiS table for each boss will result in a lot longer fullclear than necessary, due to all the waiting on relogs. Not relogging constantly can shave at least 15 minutes of your overall fullclear time.
Best example here is dragonhunter on gorseval. It can be hilariously strong, or it can be outdpsed by a condi dps build. For dragonhunter to really shine, it needs short burst phases. If you for example however run with 2 minstrel chronos, 2 druids, then you already have way longer phases. If your cc isnt instant - and I mean instant... not < 10 seconds - then that requirement isnt met at all. If too many people get egged in last phase -> not good.
In a static, you can run speedclear strats, because with practise together you get the timings right... when to burst, how much to cc.. etc. In a pug, thats nearly never the case.
Just switching dps to BiS, without actually meeting the necessary strategy requirements results in just difficult kills, without any time saved. On the contrary, in my experience with monday reset fullclear pugs, it results in MORE time spend due to failed speedclear strats causing longer phasing times - or even wipes.
BiS dps builds are build in a way that sacrifices as much utility (cc, invulns, aoe) for as much boss dps as possible. Lets take Samarog or Sloth for example. The longer the defiance bar is up, the slower the kill because you cant dps those bosses during defiance bar. It triggers me to no end, to see players using no cc - or even high dps skills - during defiance bar phases. Theres only a few very rare cases that not breaking a cc bar fast can help you get a kill faster - for example gorseval with a 2nd fullhealer and mainly condi dps. Everywhere else, the faster the cc bar is broken, the better your killtime.
You could now say, but its player xyz's job to cc, thats how speedclearers do it after all as well. Well, not one good dps player will just stupidly sit there and do his golem rotation on a boss with defiance bar up "because others are supposed to cc". Because: Faster killtime, higher boss dps compared to other logs.
And also, pugs are mostly random players with different playstyles and tactics. Expecting others to bring all utility just doesnt work.
In pugs you should always bring a slight surplus of cc and utility. Bring a scourge on MO for epidemicing the statues, its not necessary, but its safe. Dont use cc skills that are part of your rotation when a cc bar is coming up, or a mechanic has to be done. Switch out your +700 dps utility skill for a cc skill. Things like that. Nothing drastic, but small changes can already help a ton in terms of getting a good fullclear time.
In addition to above mentioned factors, just logging onto a BiS dps build doesnt make you a top tier dps. On all bosses, a well played non BiS (but meta) build is the better choice to a badly played BiS dps build. Yes, even on largos.
Theres only 2 bosses that are heavily stacked in favor of certain builds in gw2 raids - and thats KC and CA where power DPS builds or burst builds reign supreme. And even there its better to bring the power dps build you excell at - instead of logging on a BiS build that you can offer barely any dps on.
Some now might say: but thats really obvious. And yes, it is. Sadly, I see more and more players hopping on the "BiS" train in the last few months - hence this post.
Also, on a personal note, a pug fullclear isnt a record run. And if you cant meet certain skipping points to begin with then its ALWAYS a faster fullclear when bringing more utility focused dps builds.