The Yogacara container universe model posits that shared reality is due to similar karmic traces or samskaras of sentient beings.this is perfectely fine,as sentient beings with similar karmic dispositions will interact with each other and have theoretically the same reality(theoretically this is possible,but for this to happen in reality especially without interruption for infinite sentient beings without error is very improbable),but there must have been a time where this series started.i.e the series of karma-samskara->appearance cannot go into infinite regress.and there must of been a time when infinite sentient beings interacted with all of each other or produced the same samskaras leading to future shared realities before a similar shared reality could occur, to produce the series of a similar reality,but one must ask how this is possible if a shared reality is only due to shared karma or samskaras and past interaction(wich is only possible with similar samskaras and karma anyway).as again,you cannot go into infinite regress of samskaras->appearances and appearances-> samskaras ,there must have been a starting point.
if you say that''No''we are fine with infinite Regress and hold unto it,it must be asked how this is possible as william lane craig has shown that infinite Regress is an impossibility as an actual infinite can never be reached,as soon as you reach a point you must keep going as an infinite can not be finite.
the exact same karmic seeds sprouting simultanouesly (wich is just as improbable as what I positied earlier,i.e their sprouting simultanouesly in infinite numbers of times for infinite group sets of sentient beings)produce a shared reality,but there must have been a time when sentient beings all interacted with each other to produce the same karmic seeds for a future association,but this would have to be before the initial series of samskaras-appearances and appearances samskaras started,but this would be impossible as there could be no shared reality without similar samskaras/karma .
again if you claim that samskaras and karma have no begnining point,then it must be shown how this is the case.
and even if it didn't have a beginning point,and infinite regression without a starting point was possible,it must be asked how shared karmic seeds sprouting all happen simultanouesly in infinite cases since beginignless time without a single error.even if you assert that there must be specific conditions that create a similar appearance due to a similar samskara creating an appearance,how can this happen simultanouesly for multiple sentient beings without interruption?since beginingless time?even if infinite regress were a thing,this occuring would be so improbable that it would be impossible.
I just don't Understand the reasoning behind such models,it would be dependant on literal infinite regress(literally)and even if this were possible winning the lottery infinite number of times without interruption (since although similar samskaras would produce similar realities,no samskara can be exactely the same unless there were prior association wich cannot go into infinite regress,and even if it could the chances of this sprouting of the same samskara/karmic trace occuring at the same time in near infinite cases without interruption since beginingless time without end would be so improbable as to be functionally impossible),endlessly forever AT THE SAME TIME.
Again,lets assume shared samskaras exist and that two samskaras can be exactely the same without prior association,their sprouting simultanouesly without error infinitely(i.e for near infinite sentient beings) forever would be basically functionally impossible.no error at all?no mismatch between similar but not not same samskaras producing the same realities at all?in any case?since beginingless time?and without end?
by Successive addition infinity cannot be reached at any point in time,because infinity is not finite.going backwards it cannot be posited in a chain of successive series.I'm not saying that time had a starting point just that for a successive addition causally linked chain to exist,there must be a starting point.
Im not saying that samskaras producing the exact same appearances without fail endlessly for ''infinite''numbers of sentient beings is impossible.it is just HIGHLY improbable as to be functionally useless to myself.its like me being blind and fixing a rubix cube for trillions of kalpas every 2 minutes without fail,but without end or beginning.its perfectely possible,but highly improbable.
the model that would make most sence would be a realist model like that of the Theravadans wouldn't it?