The point of a resume is to elaborate on the skills mentioned and required in a job advertisement.
The bullet points on a job advertisement are largely exaggerated random fluff written by HR. Practically speaking the actual requirements are very different and more based on a general understanding of the position and company.
how you fit each skill/point of a job ad
That's not a very viable strategy at all for 99% of developer jobs. It can make sense to have different resume versions for categories of jobs (i.e. SWE vs. data scientist, or backend vs. frontend), but nobody tailors their resume to literally try to map onto the bullet points of a job ad (unless if there are particular bullet points that are highly substantial, like say you are applying for a position to help make X video game and you made a super famous mod for same video game).
More likely than not the recruiter or hiring manager reading your resume doesn't even remember what the job ad exactly said, except maybe for very broadly the level and domain of the position.
The other exception is that you arguably may get something out of generally including keywords in your resume, perhaps in your skills section, that you find emphasized in the job posting. That isn't really mapping line by line and isn't an impediment to a 1 page resume at all. Whether to do this depends on time tradeoffs.
I guess it wouldnt hurt to try this mass apply method.
It's not an either-or between mass-applying and tailoring to job ad bullets like what you mentioned, though I'd say that the tailoring of your resume is only in select cases to general job categories and most of the non-mass-applying strategy for jobs involves things like getting referrals and contacting recruiters on linkedin.
I want to be a bit blunt though and emphasize that what you said about trying to line up bullet-by-bullet to each job ad is utterly ridiculous and something you'll quickly realize as absurd once you get more experience applying to jobs. I'm not saying this to be rude - I just want to break any dunning-krueger that might be holding you back from being successful in the job search. The "map it to bullet points of a job ad" tactic is analogous to someone thinking you need to ask to use the bathroom in a college class, it's just a dead giveaway.
I'd strongly suggest going through the pinned posts on#339595755851612161 and then posting your resume on #973598253620789308