Honestly im shocked no one here has said it directly. Though indirectly they have.
youre exhibiting major lack of knowledge and understanding of the game, you don't know or Titan abilities and label something unknown as too strong or broken. Hard ai is so simple to beat it's unplayable in my opinion.
now I don't expect you to be an expert but when you start bashing a game for whatever reason I do expect a little time put in to learning said game and trying diff things. For instance you losing to advent rebels, how about playing them. Learning their tech tree and Titan, cap ships ect?
An example is a block of illuminates, repulsors, eradica, defence ships, some destr and a bunch of their t5 healers(don't remember the name now) it's insAnd. You outrange almost anything and can chain push everything back out of their range. And if you're good you can warp or move some repulsors around to blob the enemy cluster more so your eradica can burst them to death.
you mentioned a fleet of yours with 30 something ships and bombers with a Titan. Think a lot bigger Man. In multiplayer of you don't have 100+ ships in 15-20 mins on Wing or star bases up in 10-12 as suicide you really don't have a chance.
so aggressive rapid expansion against ais until you get a nice choke point, fill it with a star base and repair platforms and whatever sparkly defences you want. Have a balanced and synergised fleet. the advent one is just an example of good synergy. There are others. Once you feed your caps and Titan a bunch you can role over the cpu quite easily.