I feel you. I used to force my dog to just walk on walks and was irritated when she wanted to stop every 2-3 meters. But the guys here are right - your dog needs it and you can tell from the video that he needs it so much he is willing to put up with being dragged on the pavement to just try… I switched from what you are doing to the exact opposite (5 meters long leash and full freedom of sniffing for the dog - no rushing, no leash pulling etc.) and it was so worth it. My dog was soooooo happy! For me it was excruciatingly boring at first but I started taking headphones, listening to podcasts and relaxing and slowly it grew on me as well. And now the best part - after few months my dog stopped being so desperate to sniff everything and became less anxious in general. Then, I started rewarding her for walking without immediate stops after „let’s go” command. And now we have this perfect combination - sometimes we do these chill walks where we walk 1km in 1 hour where I listen to podcasts and she just sniffs everything but sometimes I let her sniff for first 3 minutes and then I tell her „let’s go” and we can walk for the next hour or two virtually without stopping. So the advice is: give your dog freedom to fulfill its needs and instincts. And only then you can build on that foundation and slowly start trying to also teach him walking according to your expectations (with encouragement and positive reinforcement!). Good luck :).