Actually, I was just struggling with this issue tonight! Currently I'm on 3 different types of blood pressure medication, one of which is Hydrochlorothiazide and Hydrochlorothiazide is a diuretic that helps lower blood pressure by increasing the amount of urine produced in the body, causing your body to filter out salt and water. So because I take this medication every day, I have to use the restroom a trillion times a day. This becomes more of an issue when I go to the movies, which is every Tuesday (all of my furry friends meet up every Tuesday for dinner and a movie). Tonight we went and seen Avengers: Infinity Wars (which is long as hell!) And I always wear a diaper to the movies. With how often I have to use the restroom during a movie, not wearing a diaper would mean getting up 2 or 3 times during the movie!
So I go to the movies diapered so that I don't miss the movie. The problem is, I usually have to go so much that by the time the movie is over, my diaper is ALWAYS at its limit and I'm at risk of leaking at any minute. Matter of fact, there have been several times I had to put a towel down on my car seat because I knew the second I sat down in my car, my diaper was going to leak! Tonight it was a real issue because the movie was so long that I could not risk the diaper leaking during the movie. I had already wet twice(I'm talking 2 full bladders worth, the kind that is difficult to hold) and when the 3rd full bladder crept up (which was towards the end) I decided to make myself wait till the credits so I could rush to the bathroom and use the potty afterwards (since my diaper was already close to the limit and wetting anymore could have been disastrous) but when I got up I was already at the point of desperation where every step I made actually hurt to hold in. Once or twice on the way to the bathroom I let a little out just to relieve the pain of trying to hold it that long. Once I finally made it to a stall and attempted to pull down the front of my diaper just enough to go standing up, I tore the plastic on the front of the diaper.
So to answer the question, yes! It is VERRY necessary to have diapers available that will absorb 2000 - 3000 ml of liquid and on top of that, I think diapers need to also use thicker plastic! Currently I'm wearing Tykables overnight diapers (an older version that I bought a little over a year ago that I've now heard have been slightly re-designed?) And while I have no clue how absorbent they are exactly, at one point I remember they pushed the boundaries of absorbency and they are not absorbent enough (the plastic isn't thick enough either). Regardless of what diapers I end up buying next, I will most likely invest in diaper stuffers just so I can feel more confident that my diaper will be able to handle the amount of wetting I will be doing while at the movies! For me, the more absorbent and thicker they are, the better! I'm pretty good at hiding the diaper poof and if I end up with diaper butt or a diaper outline then so be it. People are not that observant in public spaces!