Transaction time was arbitrarily set to allow time for a majority of parties on the Internet to verify transactions. It is a trade off of speed versus security. It was picked as a common denominator so that people on the opposite side of the globe and on slightly slower connections can participate in the verification process. That's why changing to PoS doesn't affect it.

Network capacity isn't affected because the amount of data exchanged is the same.

Gas prices isn't affected because gas price is only correlated with the transactions per second (which isn't changed as transaction time isn't changed) and demand and supply for transactions. When lots of people need to make transactions, demand goes up and price goes up. Vice versa. This is the same with other chains too.

Some chains intentionally lower the transaction time to increase throughput to achieve a lower gas fee, but the disadvantage is that only fast peers can verify the transactions fast enough which leads to centralization.

The "only" thing that change was the consensus algorithm.

That's good software engineering practice when you have hundreds of billions at stake. Minimize the bug surface.

Furthermore there are other concerns, Ethereum prides itself in running on the most modest of hardware. Many stakers are staking on Raspberry Pi 4.

A blockchain with large transaction speed require very powerful machines. It becomes impossible to sync with less than 1Gbps of bandwidth and storage cost becomes prohibitive.

Doing so before implementing state expiry/rent to reflect the cost of storing data in a blockchain will reduce decentralization as hardware requirements require professionalization of node operators.

Furthermore there is the rollup-centric roadmap for future scalability: https://www.reddit.com/r/ethfinance/comments/r26hhv/rollupce...

They could go faster, but then they would be like the centralized Solana chain which is controlled by VCs. High throughput is easier using a centralized data center.

Decentralization is good and is challenging to scale. I see eth making the right moves to keep the chain decentralized and accesible to those running nodes at home.

Solana has a higher nakamoto coefficient than ethereum. It’s faster due to higher base validator requirements and technical improvements (such as proof of history, etc). Which makes sense as it’s a newer chain.

There's a tradeoff between decentralization and throughput. In the extreme, only people owning entire datacenters could operate a full 'node' that would be processing 1 000 000 TPS.

Slowness is not the mechanism, ETH had ~13 second block times before the merge. Bitcoin is slow because the difficulty is targeting longer block times, not because of inherent need for slowness. Difficulty is only required so that adverserial agents (with less than 51% of hashpower) can't rewrite the chain and change transactions.