There's a general critique of 4x games that they reach the tipping point prematurely, and then you know the game is won.
I'm 70hrs into my current campaign, and prior games would dictate I'd won. So I duly started giving away fleets to allies and generalising my ships defences to eek out the current game for light entertainment. However I've just seen a fleet of 4 huge warships deep in my territory. Looking around the map the show trickle of enemies breaking through has changed to quite a few planets under siege.
Basically, I'm f**ked.
I think if I wind back about 20hr and stop sending heavily armed missionary armadas off to distant sectors, and get back to optimising for my immediate enemy, I can win.
If I'm right I think that speaks to the game staying competitive for longer.