I've recently started a 1.5 Utopia playthrough with a fairly standard democratic Human civ, and I feel I'm losing traction again, just like the last time I played.
I start exploring, colonize 2-3 planets, build some frontier outposts (not many due to influence restrictions) to enable grabbing resources from a few more systems, surveying an outer ring of systems all along, researching anomalies and finding a couple of alien civs. My energy and mineral production grows and I can more easily develop my colonies, build mining/research stations and support a larger fleet. Around this time I have enough tech to upgrade my corvettes for the first time, and build my first destroyers.
And then I hit some kind of lull. My colonies are soon developed as much as their population growth allows, so building new stuff becomes a sporadic task. And this is when I start losing traction, even though I don't think I've even reached the mid-game: what's there to do other than continue teching up, survey ever outwards and maybe pick a fight with a neighbour, just because?
I could theoretically colonize more planets, but at least on the default map settings, yellow+ worlds aren't common at all. So there aren't any suitable candidates anywhere near my space. Mars and another random planet can technically be terraformed, but for a truckload of energy and a second technology from who knows how far up (down?) the tech tree.
Thoughts appreciated.