I've been stopped off in the Progressive Era for awhile, now.
One of the first new things I ran into in the Progressive Era was 2 lane streets. They're needed for some of the new structures. I don't even want to give up the space on my 'gridpaper' to make 1 lane streets. Another, was, too much of a shortage of production goods to progress without being bottlenecked while waiting for goods.
So, I decided to stop Era progression for the first time since I started playing and stock up on goods before entering the next Era.
Well, what to do with the Forge Points that start stacking up in the meanwhile... Can't waste those and the ones that come every hour only stack up to a quantity of 10.. So, why not finally put up a Great Building. Been collecting blueprints for them ever since starting the game. Why not finally use a few.
Once a Great Building goes up I have a place to sink my Forge Points while building up supplies and other resources for the next Era.
The 1,000's of Forge points that go into these buildings will raise their effects. For example a Great Building that gives 3% attack/defense bonus goes up to 6% on the next level, then 9%, and etc. The bonus goes up fast at first and then it takes increasingly more Forge Points to level up a Great Building.
Great Buildings only go up to level 10 by default (which takes 1,000s of Forge Points) but I've seem them well over level 100. For each level beyond level 10 a Great Building requires a full set of blueprints. To build a Great Building at all, I have to have a full set of blueprints. In the course of getting to the Progressive Era and doing things that gain me blueprints (buffing neighbors, doing quests..) I already had stacks of blueprints to put to use.
By donating my precious Forge Points to other people's Great Buildings while using some basic math skills.... I get the chance to get even more back than I gave... that go into Inventory (a seemingly infinity pool so far).. instead of the puny 10-limit pool where my hourly Forge Points go. This is what incentivizes everyone to help everyone and it's pretty effective. It also gives me a way to stockpile Forge Points in inventory to go along with the other resources I need to progress through the next Era.
By playing the Great Building mini-game while I produce and trade for the goods I need to progress through the next Era I should be able to complete the entire next Era minutes after I start it - instead of weeks or months.
Then, I upgrade my entire city with the latest Era structures while also going back to the Great Building mini-game to stock up for the next Era.
Rinse. Repeat.
No bottlenecks during Era progression. No waiting (weeks or months) to discover new technology while fighting against new tech with the old tech from the last era, and, I can produce goods and cash with the latest tech right away as I stockpile up for the next Era. I'm never broke (seems to be the opposite) and I'm always at my peak or waiting for the latest buildings of my Era to complete.