Speaking of gas fees, are they still a thing now that they've made the move to proof of stake? Since confirmation takes no energy now and can be done at comparatively infinite speed it would make sense for transaction fees to practically vanish.
And they can't just flip a switch making it go N times faster right now, because transaction execution is a serial bottleneck — a "full" Ethereum node can only evaluate transactions at the speed of a single pinned CPU core, and the average CPU's single-core performance isn't going to become orders-of-magnitude faster any time soon. So there is currently a fundamental limit on how many transactions the network can execute per second, regardless of how they're packed into blocks. (And also, even if there was no such bottleneck, the per-node chain state would also then be growing N times faster, which causes its own scalability problems.)
Sharding will fix both of those problems, making the chain into N independent shards where any given "full" node only has to sync some reasonable subset of said shards, and where a node syncing multiple shards can run those syncs independently in parallel (and so — presuming a large number of shards — can use as many CPU cores as are available.) But sharding is not done yet. So gas fees remain for now.
There should still've been a massive speedup to block confirmation, no? I thought that the final mining part had to be applied to an already computed block, which would be sequential.
Block times on Ethereum were already very long compared to other Ethereum-alike blockchains, to reduce the impact of mining processing on throughput (i.e. if block time is 10s, then you only need to deal with mining overhead once per 10s period.)
Combined with the fact that people were spending exactly as much on GPUs to accelerate this process as profit margins would allow, and you'll find that not that much wall-clock time was really being spent per minute on the sequential bottleneck of mining. It's the aggregate CPU time that was being spent on mining that was economically and ecologically damaging.
But well as the other guy points out, seems like the bottleneck that creates scarcity is the single thread processing of transactions which I wouldn't have guessed, apparently the network is still actually that overloaded despite the speedup of not having to brute force the final hash thing.
The amount spent on electricity in PoW is determined by the reward not the other way around. And from what I gather the same applies to PoS, except that, instead of spending electricity, virtual tokens must be deposited somewhere, but again the amount that will be spent on these tokens is determined by the reward that the depositors expect to get.