Originally Posted by
gaz1966
Ignoring walls for a minute, it costs 35.95 Million more gold to upgrade the defences at TH8 than it costs in elixir to complete the lab and upgrade the barracks. That means, just to finish the defences, a TH8 will farm roughly another 33~35 Million elixir whilst doing so. That's without touching any walls. This is why TH8's end up farming (near the end of their time at TH8) with mass dragons or pekkas or anything that is elixir heavy, just to try and burn it up.
It's also why a lot of them feel that they should be able to spend it on walls. However, those fat elixir storages are food for the early TH9's who do not have the camp space, spells and troops to hit each other just yet.
And no, not every TH8 will attempt to max everything, or do their walls but even trying to get several maxed defences will end up filling the elixir storages for them. The game needs that surplus at that point to allow progression further up.