There are probably thousands of people applying and it’s like a lottery ticket whether you will stand out enough for your resume to even be seen unless they are looking for a specialized skillset. No full stack or front end development is not specialized.
A key goal of the job board is to allow candidates to see which companies are hiring and which positions are open. This is the most important thing to start with.
What strategy a person use to apply would vary. An experience individual would reach out to their contacts who work in those companies for a referral or find ways to reach out the hiring recruiter or manager to increase their odds of success/interview for reasons you said due to high competitions and candidate pools. On the other hand, for companies actively hiring and with many openings, e.g. Coinbase at the moment, a simple cold apply works just fine to get you to the door of interview.
With hundreds if not thousands (not exaggerating) of candidates?
Of course, as you said, it is more effective if you have connections or have gotten cold outreach by recruiters. But my point is that cold applying still works and quite some folks land their jobs this way.
The best way to secure remote work is to first develop an in person relationship.