Hi- I have slightly similar background. UC from ages 9 to 29, low grade dysplasia discovered at last colonscopy, I was urged to remove colon by my conservative Doctor at the time. The surgery was back in 1992, 2 step, and laparoscopic was not an option. The surgery was elective but my surgeon found that my colon was dissolving in his hands from inflammaton when it was removed, so toxic megacolon would have killed me before cancer, in all likelihood. I deteriorated badly and the inflammation spread in my last few years with UC.
After 20 years with UC and 23 with a J Pouch, I can tell you categorically my quality of life with the J Pouch is MUCH better, this despite battling pouchitis for 20 years (which I have mostly kept in control with antibiotics) and suspicions of Crohn's due to a small swath of inflammation in my ileum above the J Pouch. This has been called questionable and more likely the result of SIBO from backwash stool due to narrowing at the J Pouch inlet.
My only regret is I wish I had done the surgery sooner.