I don't get inspired much from video game RPGs, the opposite really, I often find them frustrating and restrictive. The big exception is TES3: Morrowind, in which I've sunk untold hours of my life. The setting itself is the biggest reason. Vvardenfell's shroomy flora and chitinous fauna are arguably the designers using the limitations of the time to their advantage. But it succeeded in making a world with personality, more memorable than most of the characters who inhabited it.
Another reason is the layers of abstraction, something the game is often criticised for. But I liked having no voiced lines and dialogues more akin to a cross-referenced wiki of lore. I found myself roleplaying how I moved; what items I kept and which ones I sold; which ones I stored in my footlocker at the guild, or placed on the bed... I filled in the blanks because the game would almost never contradict it by putting words in my mouth or force my hand. I could even deliberately fail missions if I found them unjustifiable, and the game kept going with nothing more than an irked guild steward and losing out on their reward.
Morrowind wasn't an immersive sim in the strict sense, but it had open-ended systems for you to toy with. Many of the games that do "qualify" for this nebulous term are also very inspiring in how they design problems and obstacles. By presenting the player with systems, and make these systems interact without each other, you should in theory be able to offer your players a satisfying freedom within bounds. And it'll make you be careful how you formulate your victory conditions:
If you ask your PCs to act as hired muscle to cash in a debt, there's numerous way they could go about scrounging up that sum of money. So you had better not build the rest of your scenario of them confronting the debtor. And if your NPC physician require a lot of bodies for dissection, they could hit up the local graveyard and rob the freshly dug plots. But they could likewise murder hobos. So if you've hidden a McGuffin inside a specific coffin, you need to define the "victory conditions" so that they must seek out that specific grave to proceed. Plot developments that work perfectly in a fixed narrative - Scene A leads to Scene B which leads to Scene C - is simply to unreliable in TTRPGs. Coincidence is fine, but must be left to the dice!