Continuing the conversation here as it would be off-topic in the other thread
You can already play quite easily without an Arc if that's what you want to do. I had tried a city without Arc going through the Ages back in 2017 before all this recent power creep. I have also seen players quite recently start commenting they're considering playing without an Arc.
It just makes so much more sense to leverage the Arc to circulate around Forge Points than it does to not have an Arc at all if the goal is min-max'ing rapid growth. Which at the start is exactly what you want to do.
- You don't need an Arc to send and receive 1.9 (you just need the production to cover contribution cost)
- You don't need it for blueprints, it would take a bit longer but there are so many Blueprint producing buildings anyway
- You can get very close to matching or even outproduce Arc Lvl 180 for Guild Treasury Goods with the Royal Bathhouse + 1-4 Finish Specials, depending on if you're doing it with or without Blue Galaxy.
- I already have 3 x Autumn Vineyards in the Space Ages so that already covers the new Great Buildings when they get released without needing to contribute to other players.
The two things removing the Arc would effect for my city is
Rivals (medals cost to complete Guild Expedition fast enough to get through Rivals is pretty expensive in Space Ages) and
contributing to fellow Guild Members prior to my city collections being ready for the day.
So yeah, I'm keeping the Arc. It wouldn't make any sense to remove the Arc if I'm contributing to other players Great Buildings - and that's exactly what I would expect to do as part of a Guild.
But Klods is right that if it gets to the point where the only purpose of the Arc is to find somewhere to dump Forge Points then it's going to diminish the need for an Arc. New cities make a lot of sense to grow as fast as possible, but 5+ year old cities are in an entirely different phase of city growth and we're now seeing some cities pulling out 20k+ per city collection without ever touching Finish Specials.
And the Hub Great Buildings can easily cover that kind of Forge Point collection without needing masses of Blueprints. I can see one Stellar Warship on Beta used 13k Forge Points from the owner on level 9 > 10 despite the contributors paying +/- double of what 1.9 would require on their contribution spots
The bigger problem with Stellar Warship is going to be
Supplies, not Blueprints. If you want to get (for example) level 100 Stellar Warship you also need 16.380 billion Supplies. Though you could raise the Lighthouse of Alexandria to lvl 100 for 47k Forge Points to help cover that
At this point the Great Buildings seem to be more a guaranteed production of something specific so if the next best-ever Event Building removed something from the production cycle we still have something producing X rather than Great Buildings being must-have buildings.