My experience on Scenic - September last year. 14 night cruise
there was a couple of times docked next to another boat but not very often - also this might not affect you each time depending which side of boat you are on, you may be on the outside not the next to the other boat side.
I am glad I opted for a balcony - the window is quite large. the balcony is small but large enough for 2 chairs and a little table for drinks, book etc
I enjoyed sitting out there sometimes i n the morning before breakfast or for a little while i n the afternoon before dinner - and the room, although small, did not feel claustrophobic with the large window.
We sailed sometimes during the day and sometimes at night - but I enjoyed sitting out there whether we were moving or not.
IMO it is not just the scenery view, it is also the fresh air and watching the (still) world and sometimes chance to sit separate from your partner - he could be watching TV or something on his tablet , for example, while I was reading outside
There are quite a few threads on here about pros and cons of balcony/french balcony rooms vs aquarium class - and people wit h opinions on both sides.
To me, it was worth it.