Revert default LocalBlockValueBoost to 0

[dataalways]

What type of PR is this?

Feature

What does this PR do? Why is it needed?
Reversion of #13772

Since the geth team made an opinionated decision to, by default, enforce a 1 gwei minimum tip and intentionally exclude over half of valid transactions in their locally built blocks (approximately 100 transactions per block) it may no longer be a benefit for censorship resistance and network health to encourage more local block building.

Since this geth behavior is already live on the network, we should consider whether it makes sense to revert LocalBlockValueBoost to 0 if geth decides to maintain the status quo.

[CLAassistant]

All committers have signed the CLA.

[terencechain]

Something to note:

1. Geth is not the only execution layer client Prysm can connect with.
2. Geth's default can be changed, but default is still powerful. Perhaps all EL clients should reach a rough consensus on this at ACD.

[dataalways]

2. Geth's default can be changed, but default is still powerful.

Anyone who is going to consider changing geth's default is likely someone who may change the LocalBlockValueBoost default. imo defaults should be chosen to pair with EL defaults.

[karalabe]

Meh, now you're being overly dramatic.

Geth always had a default of 1 gwei for block building since Frontier launched (actually, it was 50 gwei during Frontier and was reduced to 1 gwei after I rewrote the txpool). The "opinionated decision" was a simple bug fix as some PR broke the enforcement of the minimum tip.

I also mentioned that it should be brought up at ACD of what the best default value if if 1 is too high. But yeah, telling that to you 3 times is not enough, so now we're at 4. But hey, if you post enough spam across the entire ecosystem maybe I won't notice one.

[karalabe]

There ya go ethereum/pm#1043 (comment)

[prestonvanloon]

Added "blocked" label until we have a chance to discuss publicly at ACD.

[prestonvanloon]

ACD has concluded with a resolution that the minimum transaction fee tip will not be standardized. I feel that changing the default value of LocalBlockValueBoost is another opinionated decision. In fact, we probably should not have changed it so quickly in #13772.

I believe we should leave this flag value alone, unless there is some compelling objective data and arguments that support changing it again (to zero or otherwise).

[dataalways]

Agreed. I intend to (soon) post some empirical stats on the effectiveness and the costs associated with the flag to help inform future decisions about default values (good arguments for both raising or lowering), but this PR was premature.