I tried boots, at some point. We seem to grow rocks in this part of the country. Gave my horses abscesses that would pop out around the heel or the hairline. I tried a few brands, even custom. My speculation is that tiny pieces of rock/sand would be kicked into the boot and rub. Both are shod now, one just in the front. No more abscesses.
I did keep the boots, though, and use them when somebody pulls a shoe while I’m waiting for farrier to come.