if instead of eating it all, he sold it
But he didn't, so it was more of a chore than employment, and made even easier thanks to his cheat skill and past knowledge.
He probably will later on, because just mooching off some grasslands would make for a boring story. Or perhaps not? I mean, there are stories about these MCs who go to great lengths to avoid actually going to work.
He's also studying and working out to get stronger, so even if people point out that he isn't technically employed, he crosses out the rest of the letters on that acronym.
That's not what these letters mean. The 'education' and 'training' are specifically about academic education and vocational training - things that raise your qualifications on the job market. After all, employers largely don't care if you read or work out, they want diplomas and certifications that prove you're worth hiring.
Networking is also often a perk of pursing institutionalized education. In MC's case, being a complete nobody from a poor side of town and his 'cursed black hair' already limit employment opportunities. People would be wary if he started peddling his grasses out of the blue, but if he, for instance, found a master to take him as an apprentice, he'd have a chance to build his renown.
Overall, rather than complete idleness (nobody can do nothing all the time), neetdom is a civilizational phenomenon that involves comfortable survival on the fringe of society without subscribing to the daily grind of students and wagies. MC has a decent shot of making that work - putting food on the table without making any money.
