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 !
last time I checked the size was about 4 months ago and blockchain size was 60+GB in a non-prune mode (or whatever they call it in ethereum world) and it is rising at an alarming rate. I think it should be about 80 to 90 GB today. and in 3-4 years it can easily be 200 GB or more.
this is what most people who are so happy about fast altcoins forget! and that is the size of the blockchain and how fast it grows. imagine ethereum having the same or even half the number of transactions bitcoin has and remember that block time is about 14 seconds.
now imagine if ethereum is attacked with spam transactions the same way bitcoin is!