Something to add here is that Int is a big part of character memory and, as such, even remembering things that you're told is an Int-based process. Has your character seen someone work on something but doesn't have the skills or know-how to do it directly? A low Int character likely wouldn't bother trying to grasp the fundamentals and, if they did, who's to say that they would manage remembering how so-and-so did such-and-such? The opposite is the high or moderate Int character, who may very well come away with newfound knowledge in having seen someone work, even if they're too unskilled to do it themselves.
On top of that, I second alittlelonger's advice on quick Google searches for high Int and low Int equaling poor decision making. Jump around, do baka shit; make mistakes anyway, but make more with lower Int and enjoy the ride to higher Int by learning from those mistakes ICly. Or don't! The choice is yours.
Perception's my favorite stat in the game because it's (hot take) so well-represented already by limiting your character's ability to notice what's going on around them. Are you a high Per character? Pose that shit! Don't just "gl name" on your end- catch people and things out of the corner of your eye. Turn an ear to a conversation to make it known that you're tuned into it.
This isn't some hard rule where you have to emote every time you look at someone, but if you're wanting to express how perceptive your character is? Let people know that you're the type that watches and listens. Maybe even set a @temp_place to show that you're watching faces in a crowd, taking in the details of vehicles passing by, or some other twist.
I do know that keeping up with scroll can be difficult in some situations and that it might feel like it reflects poorly on a high Per character. Even still, someone who keeps up with everything around them isn't necessarily any more perceptive than someone who can read a single person VERY well. If you as the player find yourself in a position where you're better with one type of "perceiving" over the other? Own that, specialize in it, and make it their thing.
I'll bow out on advice for this because, admittedly, it is a very tricky one to me. You're not alone here. I've had characters across RPGs with low Chr that seem to be more likeable than ones I've played to be high Chr and vice versa.
Something that I've noticed is that low Chr characters (or characters that I perceive as low Chr) often don't talk a lot or interface much with others. That they play low Charisma as being introverted or avoiding interaction. While that's a surefire way to make sure that you never come across as charismatic, I'm not sure that it's best for longevity in a game like SD.
Mileage may vary depending on what's fun to you, but I think there's an additional takeaway in knowing that if you reach out and network, you are already projecting more of an image than someone who talks very little or waits to be spoken to.
Cinder, alittlelonger, and Reefer all hit the nail on the head in saying that nobody will fault you for working your way into any of these stats. Watch how other players with seemingly high X do their biz, then emulate, mutate, and make it your own.