Ethereum congestion possible solutions?

It is obvious that the Ethereum blockchain is congested, too many people using it which makes the transaction fees really high.
I understand that is supposed to be solved when shard chains come with ETH 2.0. As I understand that is similar to having multiple parallel blockchains.

That is all fine however I don't understand one thing. Can't the congestion be resolved by much simpler methods like for example, producing a block every second or increasing the sieze of blocks.

Now these are really simple solutions so there must be good reasons something like that was not already done. My question is, what are those reasons?

Thanks.