The type of rock you ride on will make a huge difference in whether shoes are needed or slippery.
Steels shoes are very slippery on granite rock. I'd rather be barfoot when crossing large granite slabs than have steel shoes on. Borium or drilltec does wonders to help prevent those shoes from slipping on granite.
Aluminum shoes are soft and really grippy on granite. They are great if you ride a lot of granite slabs. But they wear fast.
The Polyurethane plastic shoes also have good grip on granite.
On sandstone, I find my barefoot horses slipping and sliding . Steel shoes bite into the soft sandstone and give better traction than being barefoot.
Boots work, But they are expensive, You will loose the occasional boot if you bushwack thru rough tangles of trees/shrubs. In very abrasive materials like sandstone, I find the boots wear out pretty fast. If you are riding down a clear trail or gravel road, they work great.
Barefoot horses need to be trimmed on a much more frequent basis. Probably every 2-3 weeks during the riding season. If you let the hoof wall get long, it will pry back and cause pain as dirt packs into the dirt groove and white line