There is a trend to go back to nature for your horse which I think is excellent, but I also believe if you change the horse’s natural surroundings or way of going, you need to make sure your horse can cope.
I have seen many horses literally crawling, with a shuffling gait, having sores over their heels from wearing boots and many more painful results of people going back to nature, (I have also seen horrific injuries and painful results from shoeing).
Many people are offering barefoot trimming and charging a fortune without having any qualifications or formal training. You must investigate anyone thoroughly (facebook and online are excellent for this).
After the trimmer has been, your horse should have a balanced hoof front to back and from side to side, with very little removal of the sole and frog, and not be in pain. If changes need to be made to balance the hoof, this should be done gradually.
If you do decide to go down the route of having no shoes, keep a careful eye on how your horse moves. If he seems to be not as forward, hugging the grass verges or generally unhappy, you must make the decision to put barefoot boots on him. These are very expensive and again come with many issues such as rubbing and sores, like you wearing new shoes in. Your horse can not tell you so you have to be very vigilant.
If he has problems trust your gut- cut his work or put shoes on him.
Do not be swayed by yard bullies or opinionated people, have confidence you know your horse.
Saying this, many of my horses and ponies go without shoes in the school and withstand 3 hours of work most days (calm and steady), but we have an excellent blacksmith and very little road work. We are constantly checking if they are ok and looking for any sign of discomfort in the foot. If there are any signs we cut the work or put shoes on, mostly just fronts.