I'd rather not have to lean on team-mates who are always strangers to me. I also need to ask for a T3 engineer asap to get my Gateway built and that's an expensive unit when they may only have one or two themselves. And they may not want a T3 Sera in return etc. And maybe they don't speak my language. There are many issues with this as you see.
I'm comfortable with faction diversity as a concept but still curious to hear the reasoned argument why Sera is not allowed RAS on their Sacus. Being able to only build Mass Fabs to eco is a real disadvantage as they are easily killed or require extra overhead such as power and shields to protect. Then you have to have physical space to build all that.