I think TiTs and CoC2 differ in the fact that your motivation as to why you keep pushing can change, lore wise.
in TiTs you're heir to a company with intergalactic reach and influence but need to prove yourself to your dead dad through a probe hunt across the galaxy first. Wealth, influence, power - all things wraped up in a neat package, a clear goal and the way to get there in front of us. Easy to get behind.
CoC2 starts similary with a clear motivational goal. You, a young adventurer, set out for fame and fortunes yet unclaimed, stumble into the most le epic adventure there is - save the world. And we've got it all: love, murder, intrigue, demons, gods, cosmic horrors, SEX! Be a hero, stop the demons from corrupting everything and get your genitals wet while doing so.
And the thing is: you can keep it that way. You can stay "pure" and good, do the "correct" choices and continue to fight Kasyrra and her followers. You thwart plans, stop shemes, amass followers/comrades/people who owe you big time, meet gods, rebuild the ruin you call a base and generally just stalk Kas with a vengance. Because that bitch wants your soul and what better excuse to start swinging your weapon of choice around then when a demon out for your (and everyone elses') ass starts flinging shit around.
Or your motivation can change/evolve. Yes, Kas wants to rip out your soul and, quote "fuck the hole it left behind", but she's not so bad. Sure, there's rampaging demons, imps and fanatic followers everywhere she goes, she shapeshifts, deciets and lies to spread her corruption and that stunt with the portal in Wintercity was a bit of a bitch move, but can you really blame her? That poor soul- eh, demon is trying so hard to fight her nature, find a way out of its destructive cycle, get back in touch with her daughters and generally not turn this world into Mareth 2.0. Also, it's hard to say no to 30 inches of horsecock.
So you can come to the conclusion that the real bad guy was Tollus all along and join forces with Kasyrra, have a generally more lenient approach to dealing with or even employing demons and start a romantic relationship with Kas.
Your goal kinda stays the same: do the adventure thing to save the world. But now its also that if this lets you keep your soul and fuck the otherworldly demon, then all the better.
But here's the catch: While we can do this all to some extend, the lore of the world is so goddamn fucked. The power balance makes no sense.
Kasyrra is canonically one of the, if not the strongest demon from another world who rips space and time apart to conquer worlds, starting with yours, but it gets noted that even she has to be cautious or a god might smite her down. Those same gods just casually interact and walk among mortals, yet somehow get stopped by the most mundane shit. Tollus who somehow amasses armies worth of demons and cultist followers just strolls around with literally nobody either noticing or stopping that bitchboi for literal centuries. There's creatures the size of buildings, the combined rage of a wronged generation in ghost form, the equivalent of the shadow realm with sentience and more.
And then you arrive: a random fuckwit who was at the wrong place at the worng time, somehow besting demons, eldritch horrors and gods with nothing but a piece of scrap metal in the shape of a sword.
The whole premise sounds good in theory but the fleshed out version is just a jumble fuck of deus ex machina ass-pulls, plot holes and "somehow palpatine returned" shit.
TiTs keeps it consistent - you're strong but not immortal. Yes, you fight a dragon, a rouge AI or a bee-operated tank but the universe still makes sense. You make up for your limitations with technology, wit and luck - and even then you can just die if you're not careful enough. The dragon eats you, the rouge AI enslaves you, the bee-operated tank drives you over. In CoC2 nothing explains how your average, mortal ass punches a being of ethereal energy into submission yet somehow you lose when a sentient mushroom with tits looks at you the wrong way.
