When do you reasonably give up the career search?

I've been applying to jobs since 2023 with a bachelor's degree. I applied to about 1,000 jobs back then and didn't get a single serious interview so I had to take a job at McDonalds (my degree is Economics with an Econometrics / programming background). I was applying to Research Analyst / Equity Research / Data Science roles. I worked at McDonalds for about 6 months just to pay the bills until I decided to take a gamble and go to grad school for a Masters in Economics at a very good school. I was able to secure an internship as a Quant Analyst and added it to my resume. I've been applying around again for jobs as a Quant Analyst / Economist (government) / Economic Consultant or Data Scientist. Something that would put my Python / SQL / R background to work. But after about 400 applications with my Masters degree, I still haven't heard back from a single serious interview. Not even for super unknown small scale companies. Not even for a serious pay cut from the average salary for those job titles.

I'm not prepared to seek out my PhD. I have one previous research role (full time) and I haven't been networking as much with my professors or in the academia space. I was targeting and expecting a job in the private sector. I also don't want to work as a professor.

Basically, my question is for the people who gave up looking for a role in finance / consulting. When do I give up? Should I give up? People always talk about networking, but nobody seems to want to help me out via reaching out to people on Linkedin.

My success rate with my resume is literally 0%. I've edited and revised my resume dozens of times with multiple templates. I've spoken to dozens of recruiters. I'm not sure what to do anymore and would love some advice.

If I can't get a job with my degree I think my life would be seriously set back / crushed. Starting my own fund / firm is out of the question since I don't have capital. Thinking of working in construction or being a firefighter or moving to Africa or something.

EDIT:

Some people in the comments asking for my resume. Attaching an image of it now.

https://preview.redd.it/pytj4jg7sq4e1.png?width=653&format=png&auto=webp&s=f9038fc0609de4ce052e41702e9996f054de5984

The image may appear to have small or blurry text. That's only because this is a screenshot of my resume, not the actual thing. The actual resume has slightly larger text while remaining one page.

I also have an alternate version of the same resume that goes education-experience-projects-involvement-skills.