In the old days alliances fought about better space. If one group was living in mediocre space, but wanted better space, they tried to invade another group. This lead to a lot of good content. This worked, since you knew that your new target space had already stations, so that leaving your current space with it’s stations behind wasn’t a huge loss. It was also possible to relatively easy move POSes for cyno beacons and jump bridges. You had to get new TCUs and IHUBs, but that’s a price most groups were willing to pay for better space.
This changed when Upwell structures got introduced. Now leaving your space means that you have to leave Trillions in infrastructure behind, because you can’t move it. So once a group settles in somewhere, it will not leave until it gets evicted. However, if nobody wants to get better space, we have galactic boredom and just ‘content deployments’ which often fail. And the struture rigs play an important role in this. Because they are often much more expensive than the structure itself. For example, a Raitaru is 500M, but a single T1/T2 rig can cost 800/1500 M. A Sotiyo is 22B, but a single T1 rig can cost 50B. And this is lost if you leave a region.
While I agree that this empire building has it’s nice aspects, it will just lead to more and more stagnation. People will just stay in their space with very little to fight for.
However, if you would make rigs removable, it would make much more sense to move even a large group to better space. Making rigs removable would make it also easier to make changes like realigning structures, or repurposing structures much easier. It might even help to reduce the number of unused structures, because it’s much easier to take them down. One can also think about making the structures more expensive instead. That would also help reducing the structure spam.
P.S: While writing this, I realized that the size of Upwell structures makes it also very difficult to move them. However that’s still possible with some effort. However, the rigs are lost for ever.