Let me correct you a bit. The people of the other world don't actually know about job levels. As far as they know, only explorer has a level, and the reason they know that is because of the item box capacity. When it comes to everything else they just know that you have to train with a job for a...
Actually you might be surprised but the real grandaddy is this one, Isekai Meikyuu. The web novel started in 2011, a year before the Mushoku web novel. It even came out on the same web novel platform.
While I'm sad I won't be able to see more of Gobubi. I'm not all that sad that the manga has ended cause it was kinda bad. Also I honestly don't like it in these "I'm a mob/side character/villain" stories where they make the "heros/main characters" comically villainous.
I'm a "I can save her" type of guy but I don't consider street walkers to fall under the saving category. I'm more into just the crazy/menhera/yandere types. Like a wiseman once said "If Jesus can't save these hoes, why are you trying?".
10/10 it's a great manga. Anyone who says otherwise is a brainrotted zoomer shounentard that has the attention span of a goldfish. This manga does everything it sets out to do. It's a nice and calm slice of life with nice characters.