Another one of my most favourite gaming time sinks is Stellaris, by Paradox Interactive. Released in 2016 and expanded/iterated upon since 9 years, it is THE space 4X game and the first one I liked better than Master of Orion 2 (released 1996).
Explore the galaxy, meet new species and hug and/or kill them, build an empire.
It is a complex game and not without long term issues centered about performance and AI (both issues being genre staples as well). Yet it shines as the ultimate sandbox for emergent SciFi strategy, having slowly incorporated most tropes of the field. Emulate the Galactic Empire from Star Wars, the Federation from Star Trek, or the Tyranids from Warhammer 40K? Sure, why not multiplayer all of them in the same game? How about a ring world to go with that? No matter if you want to turn the galaxy in a garden of wonders or utterly wreck it, there are dozens of playstyles available. With galactic archeology, anomalies, and space fauna, the void is everything but empty.
Release your inner empire if you dare.