From Ironsworn, I have adapted the entire exploration system from Ironsworn into my D&D game in order to make exploration much more exciting and fun. And it has worked very well. My Out of the Abyss game would be far less enjoyable for the table if I ran it D&D RAW as it was written in the module.
So how does that work?
From 3:16 Carnage Beyond the Stars I have in the past incoporated their system of developing characters through flashbacks which allows the players lots of flexibility in expanding their characters into the setting.
I've seen that suggested for D&D over the years. It's not something I incorporated, if someone wants to add to their backstory or if it matters for the ongoing campaign we do that fill-in-the-blank offline because there are some people who would have a deer in the headlights reaction to having to some up with something on the spot.
From ... a damn, I'm blanking on the name of the game - you play a character in medieval europe who is playing a character in medieval Europe. So, basically, you're playing a medieval version of a D20 Modern game, only imagining that you are in the middle ages. It's all a bit meta. Anyway, they had the idea of Backgrounds, which is something I've used in many other games. In this case, Backgrounds doesn't mean where your character comes from. This means that the player can choose parts of his character to be placed in the background. It's true and it exists in the game world, but, the DM is not allowed to affect it or use it as a plot hook. I'm explaining it badly, but, for example, if your character had a horse, you could background the horse which meant that it never becomes a problem. It's never stolen, it is always available, it's just... in the background.
Not sure how that makes much of a difference or how it would work. I have seen issues with someone with a noble background who just wanted to run to daddy and use their political influence to solve an issue but that doesn't sound like what it is. Depending on the campaign and players, we do talk quite a bit about background and the mechanical benefits are only a small part of it.
Sufficiently Advanced has a fantastic skill resolution system that incorporates different time scales - a very early precursor to the idea of Clocks in other games. Haven't really adapted it yet, but, I do tend to loosely use the framework when dealing with things in D&D.
Again, how does that actually work? Complex skill challenges that can take a variable amount of time and/or have timed events isn't new.
Those are three examples off the top of my head. None of these things would have occurred to me had I not spent some time wandering through systems from time to time.
I'm not saying any of these ideas are better or worse, they're just different and focus the game on different things. That's why it's hard to discuss. Is it better if I have detailed exploration rules? Because right now I simply hand-wave a lot of exploration with narration to give flavor and focus on dangerous or interesting incidents. Would my game be better if I had a transparent political influence mini-game? I don't think so, because I'd rather just use my judgement and I don't want mechanical resolution most of the time but it might work better for someone else.
We all pick up bits and pieces of how to handle things over the years. Some from other GMs, some from non-game fiction, some from blogs or videos, for you from other games. There are more resources of new ideas and approaches out there than anyone could ever ingest. For that matter I just used Copilot what other games would do for a skill-challenge scenario I recently ran. It gave me answers for narrative-focused games, mechanics-heavy games, storytelling & drama systems, rules-light/indie games. It then gave me a quick summary and comparison and asked if I wanted more details. I know AI is new but it's just one more venue, one more way to think outside the box. I simply don't think there is one true way.