Possible my dog will never be potty trained?

I have an 18 week puppy and he’s still having accidents in the house 2-3x per day. I am letting him out a lot and find when I’m the one dealing with it he is better but my spouse is less neurotic about it. It’s been forever since I’ve had a puppy; for last 20+ years I’ve adopted older dogs that are pretty easy to train. My question – is it possible some dogs just never get it and always have accidents or am I just caught up in the puppy blues and it will eventually click with age an as his bladder matures? How common is it for an adult dog with consistent routine to have accidents?