You leave the house at 7am and you are 200 metres from the door at 7:20am. Every post, every bin, every gatepost. This is a different walk from the one where your dog hauls you toward another dog. That one has a trigger, and this one has a nose.
Sniffing is not your dog being difficult
Following a nose is how a dog reads a street, and it does calming work that a fast walk does not. A 20 minute sniffing walk can settle a dog that a fast hour leaves wired. So the goal is not less sniffing. It is sniffing you both agreed to, on a walk that still gets somewhere.
The compromise that works
Pick sniff-allowed zones on your route: the verge, the park edge, the last 100 metres home. Your dog gets those on a slack lead.
Between zones, the walk moves. Pay your dog for walking level with you, every 3 or 4 steps at first.
Teach 1 cue for leaving a smell. Say let's go, walk 2 steps away, and pay them for coming with you.
Use the next patch of grass as the reward for answering that cue. Sniffing pays for moving, and moving pays for sniffing.
Give 5 timed minutes of open sniffing at 1 point in every walk, so your dog gets a stretch that is entirely theirs.
Behaviour change is built from management plus reinforcement together. The zones are the management and the food is the reinforcement. Reward-based training has also been associated with higher reported responsiveness, which is what you want when you ask your dog to leave a smell. Reward-based methods are what the veterinary behaviour guidance recommends here, as everywhere else.
What not to do
Do not jerk the lead off a smell. Punishment-based approaches are associated with fear and avoidance, and this one teaches your dog that you interrupt the best part of their day.
Do not declare all sniffing off limits. You would be removing the thing that settles your dog, and the walk gets worse rather than faster.
Do not drag your dog forward mid-smell. Stand still for 10 seconds, then ask.
Safety note
Sniffing turns into swallowing in some dogs, and a swallowed object is a veterinary emergency. Get help now if your dog has eaten something they should not have, or is retching, drooling or straining. Book a veterinary examination if the sniffing is new and relentless, or if your dog has started eating soil or stones. Sudden behaviour change warrants one.
Today's version, in one line: pick 2 sniff-allowed zones on tomorrow's route, and pay your dog every 3 steps in between.