My now 18 y.o bird has been clipped his whole life. Had we gotten him as a younger bird, I assure you it would not have been my choice, but at this stage of life, it is what he is used to, he never learned to fly and trying to teach him has proven dangerous and traumatizing, so clipped he shall remain! He is perfectly happy, healthy and active being clipped, he simply knows no different. It's like a disability though, and he has to have "bridges" all around his area so he can move around from his cage to his play stand to his boing etc... unassisted since he can't fly where he'd like to go. Also kind of a nuisance to have to give him rides all the time since he can't get to where he wants to be by himself. He is potty trained and alerts us us when he needs to go, but unlike the flighted potty trained birds I grew up with who'd fly home then fly back, we have to drop what we're doing to rush him home, then wait for him to go and bring him back. Flying is the natural, preferred and often best mode of transportation for a bird. You also have to be sure you are keeping your bird active enough as a non-flighted bird, as their biggest form of exercise (flight) will be off the table and you'll need to be creative in keeping them active.
All of that said, what are your reasons for wanting to clip? There are valid reasons. I do strongly recommend you at least allow him to learn to become a competent flyer before clipping. Much like riding a bike, they will never forget how, but the older they get, the much harder it becomes to learn and a point could come in the future you are able or would like to flight your bird again. My dad's cockatoo was clipped for a few years when I was a toddler for safety reasons, and re-flighted once I was old enough to avoid him and picked flight right back up as he was a competent flyer before being clipped. Trust me on this one, you don't want to try to teach an older bird who's never flown to fly. Teach them while young, then clip if you feel clipping is really the best option for your bird.