So I have had a very frustrating experience a couple times now where I have demoted placing 5th place. The problem isn't that you demote, it's that you lose 25 LP when you should only lose like 7. I just placed 5th in a round where I was unlucky enough to be the first of 2 people eliminated. If I had hung on for an extra few seconds I wouldn't have demoted at all. But instead i'm down 25LP.
Now i'm put in the position of having to come top 2 in the next game to promote again when you should be able to promote back with a 3rd place finish or maybe even a 4th if you demote on a 5th place finish.
Going down 25LP no matter whether you get 5th or 8th is not a balanced experience. Getting 5th should not punish your LP as much as getting 7th or 8th. I really think this system needs to be modified because it just feels unfair.
The fairest way to do it would be to make it so that if you have say 15LP and you come 8th (losing say 40 LP) you just demote to 75 LP in the lower tier, instead of sitting at 0LP and then having the experience of 5th place costing you 25 LP. Right now instead of demoting on the 8th place, you lose 15 LP and then you lose the remaining 25 from getting 5th. It makes no sense.
It gets even worse when you recognize that its possible to place 6th lose 15 points than place 5th and lose 25.
Just make the system demote if you lose more than the LP you have and take 100 minus the remaining LP loss to give you the LP you start with in the lower tier. IE. If you have 15 LP and you come 7th and lose 25 LP then you should demote, and start a tier down at 90 LP the next game.