Ethereum? At 4 transactions per second, it can't scale to be a search engine -- or anything else useful, really.
Ethereum can do 15 tps, but to your point, scaling is being worked on through multiple tracks, most importantly through sharding, which promises to increase maximum throughput 1,000 fold.
Also, this proposal only uses Ethereum to reward contributors. The data would be stored in and retrieved from IPFS.
15 transactions per second is still useless. What's worse is that the Ethereum Virtual Machine is insecure by nature and cannot be fixed. No one should trust "smart contracts" with any money they're not prepared to lose. The entire concept of a "world computer" (which requires everyone to run code they didn't write and can't easily audit), is ridiculous.
I don't know what you're basing your claim that the EVM is insecure on. If's never had a security lapse.