look at ETH like on OIL both in build are the same.
1) To high price of oil people are looking for alternatives
2) Low price of ETH people buy ETH for services

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2nd thing is space:

Imagine in decentralized system store so much data as ETH will need
BTC have problem with 1MB while ETH want do everything from domains to dividends.
After 3-4 years blockchain size will be like 100-200GB in 10 like 10TB or more.
Eth will migrate to 3-4 bigdata centers but it won't be no longer decentralized.
More Daps more space resources needed CPU/SSDs.
Imagine scan 2TB for data records in sensible time !

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Cost changing i remember that devs were hard forking some stuff to rise costs of some operations.
Imagine u run contract and you have ammount of ETH and gas then they rise cost and you dap stuck/stop.