For basically anyone beyond the 3rd chapter who is interested in it.
It used to be 2-3 FS per world, then for a looooong time it was 7-8, and now it's over 50 FS in every single world.
Elvenstats only shows the top 50 FS per world and
100% of them got over 40K.
the groups who can't do it no matter how hard they try becuase they don't all have 400+ explored provinces.
54 explored provinces is enough to have 6 of each type and do your share of 10 chests.
To enter chapter 4 requires a minimum of 50 explored provinces.
for 166,000 points (19 chests) your FS needs an average of 25 open provinces* of that week's type (225 total explored)
To enter chapter 10 requires a minimum of 220 explored provinces.
So those groups who don't have enough provinces open to get 10 chests or 19 chests have something they can work towards quite reasonably given proper motivation.
As for the prize compounding (success making success easier), that's exactly what the spire prizes do, and it's fine.
*Not counting the possibility of using FS perks where you could bank up to 25,000 points meaning a group where everyone does 20x6 could get there.