It was never intended for high-level fighters to dominate Battlegrounds. This reins them in. The average guild member will have more of an impact now.
Trouble is this removes the motivator to keep improving. If adding 100% more boost gets me 1-2 more fights that hardly seems worth the effort. Also I can already sustain 100+ progress a day by negotiation (that is to say, up to 50ish attrition) - where this moved what I could do by fighting from 30ish to 40ish probably on my mars world.
On my CE world where I was planning to find my way over the top of the 1750% defense wall, that's now right out of the question - and not even worth trying for. I'll probably be able to fight 60-65 or so instead of 50-55 immediately. But where after much development I had planned to be able to very tediously fight 100+ fights a day, now I may as well not even bother. I'd get to 90 with the amount of effort that would've taken (probably a year's+ of events and auctions) or I can switch gears, focus on negotiations, and in a few months be doing 100+ there too.
At the high end, negotiating is more highly favored than ever after these changes.
Except of course for siege camps. The ability to fight more (and potentially overtake negotiating by doing many low boost fights with few losses) is tied more than ever to the ability to plant a *ton* of siege camps. So now the logic if you want to improve your contribution as a fighter is to power-level more treasury buildings.
I'm mostly concerned that in their quest to make things more fair, they might damage the motivation to keep improving which is what I viewed as the most important aspect of this feature.
I don't necessarily mind that attrition just keeps going up when it comes to attack boost - i just wish there was less of a "you shouldn't be here" aspect to it where they just keep sending the % up exponentially to cover corner cases where someone has found a way to keep going. Should there always be a point where you get stuck? Yea, probably. Should you be able to develop to continue moving that point significantly later? Absolutely, but right now once your endpoint is somewhere in the steep region, you may as well just give up getting stronger which makes GBG just more busywork. Or switch to negotiation where you can always go further, you just need more goods.