I've been playing for over 10 years and I've never died to server lag or dcs. I'm not saying it doesn't happen but I think it is over hyped sometimes.
In the end the game needs a refresh in terms of items and gp and any sink is a good one.
I don't think its true to say any sink is a good one because the issue with the game as a whole isn't that everybody has too much gp - the gp issue is very much pooled in a specific player subset within the end game. A sink aimed to hit everybody fairly ends up doing virtually nothing to the cash stack of those creating the need for gp sinks, but ends up a fairly decent chunk of bank for most others.
Really the only true way to actually refresh things in a decent way for items and gp alike would be to set up suitable sinks across the game, whilst removing ways of creating from nothing excessively, to a point where largely items maintain a status quo. Then purposefully and forcibly removing gold and items from the game in a very targeted manner.
Short of literally taking away peoples items and gold arbitrarily the only real way this could be done would be to create some heavy taxing systems:
For example making the GE eat 50% of items that are in excess.
Make banks charge tax based on a heavily weighted curve vs bank value - ie the curve would barely, if at all, charge people with little to nothing but the people who have the excessive hordes of gp that skew the economy would find themselves facing a significant tax until they got rid of a lot of their gold.
The only other really viable solution would be to essentially abandon ship on gp and create a new currency for the game - one that is much much much much more restricted in means of creation from nothing from day 1 and limit it in such a way that all the existing gp cannot be easily switched over and people will have to abandon wealth if they have excessive amounts. IE Everyone gets x% of bank value up to a limit of Y once a week for 12 weeks and after that 12 weeks is up gp cannot be traded anymore - but at the same time have some grindy, diminishing returns, ways to convert extra gp just to give people a chance to salvage some more if they work.
It would sort out the economy in a meaningful way that a few sinks here and there can never really do, but of course it'd come at the expense of alienating and losing a lot of high end players.