Maybe as of right now yes, but blockchain is also very transparent at least when it comes to coins like Ethereum or Bitcoin. And there are businesses that have strong analytical capabilities and in addition a lot of regulatory pressure on exchanges. Maybe it's not so easy to manipulate very soon.

What you describe is the essence of Ethereum to a certain degree. Once the decentralized applications start to function the demand will increase significantly. To accommodate that demand the price will increase.

This article explains why Ethereum has already won the race to become the foundation of Web 3.0, and will become the fundamental base layer that all major DApp platforms will choose to build on top of in the future.

"It’s hard to fathom why a developer would want to replace Ethereum instead of simply building on top of it 🤔
Ignoring the obvious motivation that doing so allows them raise hundreds of millions of dollars in an ICO…😉"

https://medium.com/loom-network/ethereum-will-be-the-backbone-of-the-new-internet-88718e08124f

Some projects migrate from Ethereum network . I think this is quite normal. A lot of projects are now on the Ethereum and for most Ethereum as the first stage in their development.

It is the second time in a year that large projects are moving on their own blockchains. Still I hope, that all the same there will be a jump of the price upwards under the influx of sharp and positive changes, that the Buterin says.

Yup slowly, coins moves on their own blockchain. Coins wants to be independent of BTC. So they each coin will have their own market value. Coins will no longer be drag down by btc when btc  goes down. This is quite clearly what is happening now. I notice this because like ethereum, litecoin and ripple are starting to have an exchange directly to fiat money. In my country you could already exchange ethereum to our fiat money directly. Quite cool right. No need to convert first to btc before ethereum. Direct exchange from eth to fiat.

You mean sharding. Sharding effectively makes many side chains, isolated from others, such that validators for some shards don't have to validate transactions from other shards. I don't see what you mean by "cause many side chains to disappear".

ETH is the best platform for smart contract, as I think. Also it have all chances to be top 10 cryptocurrency for many years

yes no doubt eth is best for smart contracts and the team made the working platform in a year without any error. great achievement, that's why its second best cryptocurrency in the crypto world
and about other project that having competition with eth is far behind from it.
eos is about to launching their mainnet but eos needs still much time to develop like ethereum
but then ethereum will developed more

Too many pre-mining tokens. The price should collapse.