Can someone have a career outside of Chess and still compete at a Master level (NM, IM, GM, etc.)?

start blogging, dropshipping or writing self-help books or w.e other bs is rewarded by the capitalist system because chess is one of the worst things you can make a profession of.  IT is essentially HIGHLY difficult to reach true mastery ( i mean top 1000 in the world, preferably top 100, not our kiddy master titles), there is an oversupply of said players and virtually NO economic demand for them. You literally have a better chance to make a living selling custom medieval fantasy weapons than a chess professional.

It has to be difficult, if not impossible, to combine high level chess with another career, probably more so now than in earlier times. Even Reshevsky, writing in 1948 wrote that "It is a difficult task to make a living from chess". He had passed up the 1944 US Championship tournament to study for the CPA exam (which he claimed was far more difficult than most chess games he had played). He went on, "Henceforth, I will confine my chess activity to vacations and occasional leaves-of-absence. Never again will I permit chess to interfere with the more important business of caring for my family." From Reshevsky's best games of chess, 1960 Dover edition, page 244.

Most CMs/NMs/FMs have other jobs/careers.

It's generally only IMs and GMs who can afford to use chess (and coaching) as their main source of income.

Kinda depends where you draw the line. My club has about 8 FideMasters and 2 International Master and absolutely no one has chess as a job. On truly top has quite rare.

There is no money in playing chess. So most playears need a job 

That was quite a big span

GM Pepe Cuenca has a degree in maths

I’m saying give or take 

Magnus Carlsen is a model, so yes it's possible.

in my country Zambia no one plays chess as a day job..all IMs from my country are not professional chess players.. they are rate at 2100 and 2300.the current local champ even draw against ivanchuk rated 2700 in batumi

Great, now I'm thinking about medieval fantasy weapons.