The reason Glicko doesn’t work is because the ratings don’t naturally gravitate back to 1500 over time like they should. Instead the top tiers just get higher and the low end gets lower. I’m in T5 and there are 350+ points between T4 and T6, so unless things change, my server is stuck here forever.
The solution should be something like this: every week, take 1% of points from T1, 0.75% from T2, 0.5% from T3 and 0.25% from T4. Add them up and redistribute 10% of that total to T5, 20% to T6, 30% to T7 and 40% to T8.