The premiere could certainly have lost 30 minutes. I think episode 3 getting an extra 30 minutes was a last minute thing as originally it was scheduled for an hour. It actually worked in it's favour for those of us who didn't realise as we were watching it was an extended episode, making THAT moment even more surprising. Surprised the final wasn't extended TBH.
I do agree in general 90 minute episodes can be a drag - it's usually better editing rather than more time that is required. Big Brother competitions now can often play out in two parts over 10-15 minutes or so when in the early years they'd often be edited down to 6-8 minutes. A longer edit usually means more filler rather than more action, especially with reality TV producers across the board obsessed with contestants telling us what is happening or has happened in the diary room (or equivalent) rather than just showing us for ourselves. It feels we get so much reality TV second hand nowadays.