Over the years, the server shapes itself in the carcass of its playerbase. Freedom in roleplay is vindictive of being "let people do whatever they want," and in practice, just as you said, that translates into dominant realms consistently crushing the small guys. We've seen how that played out in previous maps over the past decade, and on Azuras per the Urguan v. Empire war. However, this one was warranted as Urguan were the provokers in this ultimatum.
I just disagree with one thing, lowering the cost won't actually create a better story in my opinion. It will accelerate burnout by decreasing realm cost from 25,000 to 10,000 mina. This, while in practice, will improve accessibility while ignoring long term realm bloat. We've also seen this across multiple maps. When accessibility becomes too cheap for those with the aim to make meaningful nations, you suddenly have a big map with a large separation between its playerbase, short-lived groups that suddenly dissolve or get absorbed after a short amount of time.
I believe that 25,000 mina isn't unrealistic. At the end of the day, the 40+ players should be coming together to contribute financially for a new realm, a new culture, and a new leadership for their own benefits. With collective effort, with something as simple as voting, a group can, within a realistic timeframe, get the amount of money needed alongside the signatures. At ~23 minas per day per player, that's ~690 minas per month for each individual (27500~ collectively). Voting takes less than a minute on a daily basis, so even if you work a 9-5, a 15 year old Timmy cannot outdo you in that regard. It sounds practical, unrealistic, but can be done within a few months timeframe with collectivism.
But honestly, I understand. I've played the side of the losers before, the side where all that hard work dissolves just because one big guy defeated the smaller guy (me, in that perspective). It's disheartening and not ideal for the losing side. But I also agree with altering the war rules and giving settlements more jurisdiction as pseudorealms, also wouldn't mind decreasing the price for settlements, but not realms
edit; correction, 20000 mina not 25k, even lesser and much more doable.