I was reading about the Order of Cistercians the other day, and I am reminded of this passage from wikipedia:
Relaxations were gradually introduced into Cistercian life with regard to diet and simplicity of life. Also, they began accepting the traditional sources of income that monks in comparable orders used: like rents, tolls, and benefices. The agricultural operations were blessed by success. Wealth and splendour characterized the monasteries, so that by 1300, the standard of living in most abbeys was comparable, if not higher, than the standards middling nobles enjoyed.[59]
[59] Jaritz, Gerhard (1985). "The Standard of Living in German and Austrian Cistercian Monasteries of the Late Middle Ages". In Elder, E. Rozanne (ed.). Goad and Nail. Studies in medieval Cistercian history. Kalamazoo, Michigan: Cistercian Publications. p. 57. ISBN 978-0-87907-984-0. "A study [Watzl 1978] done for the Lower-Austrian abbey of Heiligenkreuz demonstrates that in the first half of the fifteenth century, no fewer than 201-207 days of the year saw extra food."
One documentary I watched claimed that they tend to accumulate significant wealth so much so that their effects can be seen on the communities that surround them.
There are probably a lot of reasons for this. Much of the profit from the work done by the monks is often captured by the institution and used to purchase land and buildings. Large monasteries might have dozens or even hundreds of able bodied men engaged in light agriculture, bee keeping, beer production, etc. and that adds up over decades and centuries.
I think when we consider productivity you might be thinking of Silicon Valley hustle culture rather than the effect a community has over centuries.
Relaxations were gradually introduced into Cistercian life with regard to diet and simplicity of life. Also, they began accepting the traditional sources of income that monks in comparable orders used: like rents, tolls, and benefices. The agricultural operations were blessed by success. Wealth and splendour characterized the monasteries, so that by 1300, the standard of living in most abbeys was comparable, if not higher, than the standards middling nobles enjoyed.[59]
[59] Jaritz, Gerhard (1985). "The Standard of Living in German and Austrian Cistercian Monasteries of the Late Middle Ages". In Elder, E. Rozanne (ed.). Goad and Nail. Studies in medieval Cistercian history. Kalamazoo, Michigan: Cistercian Publications. p. 57. ISBN 978-0-87907-984-0. "A study [Watzl 1978] done for the Lower-Austrian abbey of Heiligenkreuz demonstrates that in the first half of the fifteenth century, no fewer than 201-207 days of the year saw extra food."