It's in part true. Cookig vegetables in general reduce their fibre / nutrients. Thing is... Who cares? is not like you are reducing the benefit by 90% and if the trade-off is not eating them, I see no issues.
First link i found: https://www.nutritionletter.tufts.edu/general-nutrition/does-cooking-vegetables-destroy-their-nutrients/
Yeah. Thats the time i "legally" steal everyday.