3 kids, all been in cloth / reusable nappies. We were not militant strict. Used dispoable for night due to extra absorption. But day time use, pretty much only reusable.
Anecdotal of course, but they all were toilet trained before other kids. Whether that is because it is more noticeable the nappy is wet and uncomfortable or other factors (wife was home all the time, kids in a nursery from a young age all day seemed to lag further behind). But I think the cloth nappies definitely played a part.
Cloth diapers are expensive. My wife and I bought them and tried them for about a week before giving up and selling our stock. So for one there is a large upfront cost, and if parents can get over that hurdle, there is also the need to find a daycare that will 1. accept a child in cloth diapers and 2. be reliable enough to send back your cloth diaper investment.
Anecdotal of course, but they all were toilet trained before other kids. Whether that is because it is more noticeable the nappy is wet and uncomfortable or other factors (wife was home all the time, kids in a nursery from a young age all day seemed to lag further behind). But I think the cloth nappies definitely played a part.