Sorry to be blunt, but - to earn some money to feed their family? Just like applicants are not unicorns, neither are companies - unless you are FAANG nobody really cares about your shitty company really. (Maybe not even if you are FAANG.) If the CV matches the JD, why do you have doubts if they have an idea about the work? They obviously haven't the faintest idea, but how could they (unless your code is open source).

From the applicant's perspective, they are applying to multiple places at once. Investing emotionally at step 0 (when they don't know if their CV will even be considered) is taxing, and unfair. Once there is a connection, you can expect them to invest more, but not until then. Because they will apply to 10 places, get ghosted by 5, get an automated NO response from 4 (usually a month later), and maybe, MAYBE they get an invite to the last one. Get a conversation started first and THEN expect investment.