It's nowhere similar to SL. If a sick mother is your only reason to compare this to SL then you haven't reading webnovel very long. A sick family member as a motivation for MC is like one of the most common trope, SL is not the one that start this trend, you can go back as far as The Legendary Moonlight Sculptor to get similar trope. You now what, why not compare it here?
Main character:
SL:
A regular human that is blessed with the ability to level up by accident in a double dungeon. The author would later change it so that he's always meant to have this power.
Personality-wise, he doesn't have one. At least at the beginning of the story he was capable of showing a range of emotions. But after getting strong, the only emotions are brooding and angry. He's basically a robot after he got strong. He does show some kind of emotions in the more comedic "scene", but his default aura is chunibyo. Also very vindictive.
IATSK:
The strongest wizard in his realm, he was reincarnated into modern South Korea where monsters, levels, and skills exist by the grace of a "system". He didn't have any memory of his previous life until he had an incident with a strong monster. Before this he was working in a support role for hunters, he then with his past life knowledge became a hunter.
Personality-wise, he's charming, he knows how to deal with people. He's decisive, smart, and careful. He likes to collect people and guide and build them, and people like him. He won't hesitate to destroy his enemies, but he's also quite open-minded and flexible to make deals with them when necessary.
Story:
SL:
Standard Korean light novel. Full of powering up, full of encountering enemies that came from nowhere, and is just right on his power level. Lots of deus ex machina. Many cringe scenes which focus too much on the "cool" level. Many important scenes were witnessed by many people, so they could praise him. The main plot line is non-existent until the middle of the story. Plot armor is strong.
IATSK:
Story is quite consistent. MC was curious but skeptical about the "system" from the beginning. This would be part of the main story until the end. There is no deus ex machina, everything happened as it is without any extra content to "spice" the story. Might be boring if you're not into it, to be honest. MC has a meticulous plan from the beginning and the story is about him finishing the steps of the plan. There is also some political element to the story. There is no real "bad guy" everyone is in the gray zone, with the exception of the last monster they fought, but that's just their nature, not being evil in my opinion.
MC plan is basically separated into 3 parts. Get strong; get people that he can trust and rely on, and support them; build influence. And he manages to do all that by the end of the story.
TLDR: It's a good story about a charming and smart wizard reincarnated into the modern world. Story is realistic but could become boring if you're not into it.