The stakes depends on the signature space.
The space provided by senior member and hero members are more visible and bigger than the lower ranks.
When I was also new to the forum, I also noticed that but I don't know the history of it, probably that's it.
That caused by you need more effort to make or increase your rank from the newbie to the legendary. The history of stake created by the old system of BTT that gave you 14 weekly activity and you need a certain amount of your activity point to make you able to increase your rank. That's why there was a stake allocation based on level.