Tbh it doesn't really reduce the number of unsolicited spam calls that much. On the other hand there is a fixed list of prefixes that can be used for these type of calls that you can directly block: https://www.arcep.fr/actualites/actualites-et-communiques/detail/n/plan-de-numerotation-050922.html.
In France it's those prefixes "0162, 0163, 0270, 0271, 0377, 0378, 0424, 0425, 0568, 0569, 0948, 0949"
How dare you detective Diaz