Does anyone else have an adult dog that’s impossible to teach to stop pulling on the lead? How do you cope?

I’m starting to feel like there is no solution after a dog has grown up. Am I the only one dealing with this?

I have a 7-year-old medium-sized Cavachon who has pulled on the lead. We’re a family of three and we all walk him, which I think has made it hard to teach him consistent discipline with every person. I’ve tried so many things over the years: slowing down, stopping when he pulls, using treats and ‘Sit’ whenever he starts pulling, buying a harness and watching yt videos. Nothing has seemed to work for a prolonged period of time. Some walks are okay, others feel like he’s dragging me the whole time.

It’s getting to the point where daily walks feel more like a chore than something to enjoy. Even my mum struggles with him and she’s complained about back pain from the pulling, he’s not even a big dog.

I’m curious if anyone else is struggling with older dogs, or if anyone has successfully retrained an adult dog to walk nicely on the lead?

If so, what was your approach?

I’d love to know what others have experienced with this issue and whether people have found reliable ways to fix it. Any experiences (good or bad) would be super helpful.

Thanks in advance!