Because, really, why not put all the important stuff into one giant scene?
Below is a video with four versions of "To be or not to be" - Branagh, Tennant, Scott & Hiddleston and a second video with Essiedu's performance.
This blog post from Dr. Michael Ullyot at the University of Calgary does a nice job comparing Olivier, Zeffirelli/Gibson, and Branagh versions. Keep in mind that this is Ullyot's opinion, but it's a very well-considered opinion. He discusses both the soliloquy and the interaction between Hamlet and Ophelia.
It's worth watching this scene a few times to see what's going on here. The Olivier version below is, as far as I know, one of the first versions that includes physical violence towards Ophelia. Do you think this choice is justified? (The encounter between Hamlet & Ophelia begins around 3:50 in the Olivier version.)
Now, watch the other versions. Does Hamlet know that Claudius and Polonius are spying on him? When? from the beginning? somewhere in the middle (which line)? never? How does this influence his behaviour? Again, we are faced with two big questions: is Hamlet actually crazy? Does he love Ophelia? Did he ever? What makes you think this?
directed by Laurence Olivier, Hamlet played by Laurence Olivier, Ophelia played by Jean Simmons (1948) (Nunnery starts around 3:50)
directed by Franco Zeffirelli, Hamlet played by Mel Gibson Ophelia played by Helena Bonham Carter (1990)
directed by Kenneth Branagh, Hamlet played by Kenneth Branagh; Ophelia played by Kate Winslet (1996)
On stage at the National Theatre, directed by Lyndsey Turner , Hamlet played by Benedict Cumberbatch; Ophelia played by Sian Brook (2015)
Dying of over-Shakespeare? You can honestly skip lines 1-88. I mean, they're good and all, but they don't add that much. Suffice it to say that Hamlet is running around trying to tell the actors how to act. It's kind of funny, you see, because he's an actor pretending to be Hamlet and he's telling actors how to act. No doubt Shakespeare found this quite hilarious, but you don't need to unless you study this play again later. Just go to line 88.
NOW, pay attention. Watch how Hamlet is behaving. He's appalling, really...
And Hamlet sees him praying... but doesn't hear the confession. ARGH!
My favourite version? Patrick Stewart as Claudius: https://youtu.be/aCrq7UhVUK0
Oedipus complex rears its ugly head - but wait! Freud didn't develop that idea until the 1900s... so... Shakespeare didn't know about it... so, what the heck is going on?
directed by Laurence Olivier, Hamlet played by Laurence Olivier (1948)
Sorry about the weird subtitles - it's the only one I could find.
directed by Gregory Doran, Hamlet played by David Tennant, Gertrude played by (2009)