My megaproject ideas are mostly pretty standard. I'd build a high speed rail network across North America, and build and expand metro and regional rail systems in and around every city. I'd turn all cities and suburbs into fifteen-minute cities. I'd decommodify housing, and build ten million units of public/social/non-market housing, mostly three bedroom units. I'd link those last three policies together by building TODs around the new Metro and rail stops. And I'd build bicycle networks in every town and city and connect them to the TODs. I'd build bridges and walkways across skyscrapers. I'd put a bidet in every American toilet (uses less water than toilet paper apart from being more comfortable). Fiber internet in every home. A heat pump in every home. An induction stove in every kitchen. Phase out fossil fuels and power everything with Pumped Storage Hydropower and Geothermal. I'd make the US go Metric.
But my truly crazy, obsessive idea would be to bring back the French Revolutionary calendar. Or I'd purge all French influences from English.
I think you're confusing a bunch of distinct concepts.
Like, a job has so much that goes into it: a wage, time boundaries, a management structure, etc.
There's also other parts of a job that can be done without those things: the actual (re)productive activity, the skills associated with it. Like, you can be a landscaper as a job, or you can keep a garden.
You don't clock in to gardening, you don't report your progress to a boss, you don't get paid for it.
There's also multiple avenues for learning things. Many people learn cooking and auto maintenance in their families. People go to language learning clubs. People pick up skills on the job. People go to school. There's nothing that says that skilling needs to be in service to a job.
"Jobs" and markets are the current ways of organizing (re)productive activity in our society, but that's historically contingent.
In Marx, neither Jobs nor markets appear in his descriptions of communism. Indigenous people have and still use ritual do do certain productive activities such as controlled burns or salmon harvests. Many anarchist projects run on a volunteer basis. On the darker side, serfdom and slavery have appeared as alternatives to jobs
Insisting on the persistence of Jobs is to insist on an incomplete break with capitalism.