No. Sorry, but ageism cannot be neatly dodged with a platitude. Yes, some deaths are welcome at any age. A two year old in agony and with no possible useful treatment should not be forced to stay alive an extra day or two.
But a woman we first met on holiday lived to over 100, with reduced mobility only in the last eighteen months. She was effectively bonded labour to the family business. Her childhood, early years, and even her 70s and 80s, were full of nothing but hard work. In her early 90's, able at last to get rid of the business, and still with gusto and good health, she began to enjoy herself.
She danced, drank and smoked, played a clever hand of cards, enjoyed her new freedom to have a social life, flirted, and took holidays, and spent her money on herself, and did all she could to make up for the pleasures of the childhood and teenage life she never really had. In every way, the only part of her life worth having was the years between 90 and 100 while she still had the full mobility.
The family business had depended on her. Her ageing parents had depended on her. Her feckless siblings had depended on her. As long as the last brother lived, they needed the business with the accommodation that went with it. It couldn't be sold. She couldn't earn money for them any other way. She couldn't house them any other way. We admired her.
I think some of the most age-hating people tend to tell themselves young=useful to themselves and others, and over 50=over and done with, no good to anyone and must be longing for their miserable existence to be ended. If they met people like 'our' old woman, surely they could see that it's possible she deserved and earned those years in her 90's, and she was entitled to every moment of enjoyment, after waiting so long for any pleasure of her own?
By the way, being selfless and doing something worthwhile is possible at any age. A Russian (hard working) scientist/doctor got Covid at age nearly 80. Being healthy, he survived without much treatment. So he voluntarily used himself as a guinea pig by infecting himself a second time. The second infection was worse, and nearly killed him, but he had proved something important. Infection once doesn't mean immunity, and the second infection is liable to be worse, not minor. (And, 80 isn't an age when a person is useless, or not strong.)