I chose a long time ago to stop teaching in indoor settings (for puppy and pet obedience classes). Teaching outdoors in the community is hard but the benefit is HUGE. When we teach our dogs how to focus and listen in situations that mimic real life then your trainer is preparing you on how to handle things that will actually happen to your dog.
These situations include: dogs who sniff the ground non-stop as soon as you hit a nice, grassy field, dogs who become stressed or reactive when an off leash dog runs up to them, dogs who are over excited when they see other dogs running or playing, dogs who get excited when people especially families pass them by, dogs who want to chase joggers, cars, rabbits, etc. These are things that are likely to happen every time you take your dog for a walk.
So while in a training centre I can teach you how to get your dog to do basic obedience, I cannot teach you how to handle different situations. So my classes are held outdoors, in a new environment with new challenges every week. I will be there to help you in real time as these situations occur. The other benefit is you get to learn new places to train and how to incorporate training into your walks and adventures with your dog.
Training outside can be harder. You’re competing with more distractions. But you and your dog are learning how to navigate the world and achieve your goal of having a pet that you can take on adventures with you because they have the real world skills on how to behave in these situations.