Tim Rose who played Admiral Ackbar in Return of the Jedi, The Force Awakens, and The Last Jedi has expressed his disappointment with the way his character was killed off in The Last Jedi.
Rose was also disappointed that Ackbar, a fan favourite character by any standard, was not given a larger role in the sequel trilogy and was essentially used as a joke at the end of filming.
Ackbar's final moment before he went in to the box was a big joke about 'It's a wrap'. They just thought 'Wouldn’t it be funny?' And that was the sum total of my life as Ackbar.
Here's the full interview with YouTuber Jamie Stangroom (whose channel is well worth a subscribe, by the way):