Revenues in league one level above typically are 50% higher than revenues in league one level below.
Expenses of new teams are the same in every division.
Therefore incomes in higher division are 2-3 times higher.
Example:
Revenue in 5th division: 100k
Expenses in 5th division: 80k
Income in 5th division: 20k
Revenue in 4th division: 150k (150%)
Expenses in 4th division: 80k
Income in 4th division: 70k (350%)
Revenue increases to 150% but income increases to 350%. My incomes increased only to 200% because my expenses increased too (but of course slower than revenue).
Also in DIII they can win games, which is more motivating and fun to keep playing
Yeah, it's big motivation to beat bots. You must understand one simple thing: in every match always only and exactly one winner and only and exactly one loser must exist. In every country, small, big, middle. If you want to have more winners than losers, than only solution is always play against bots.
If new teams after one week in BB will beat old teams, then old teams will lost motivation. For example like Sharman. And number of users in Japan will be the same. So it will not solve problem with small number of users in Japan.