I still find it incredible that out of 330 million people, these two presidential candidates are the best America can do.
But it's not out of 330 million people.
The US President has to be over 35, which eliminates half of the population. The President also has to be a Natural Born Citizen; That lowers the pool still further.
Most importantly, nobody can be a serious candidate for the presidency unless they have been politically active for most of their adult life; or are famous; or are wealthy; or ideally all three.
The first of these requirements is the real kicker; It denies any chance at the presidency to anyone who is well qualified in a field other than politics or law (or perhaps economics).
Engineers, Physicists, Medical Doctors, Tradespeople, etc., etc., aren't usually able to become experts in their chosen field
and be sufficiently politically active to be considered a viable choice for presidential (or even congressional) candidacy - there's simply not enough time in life to climb both greasy poles. It takes a long time to become 'presidential material' in the eyes of the two major parties - the youngest presidents have been eight years older than the lower limit set by the constitution, and there's a reason for that. Shit, the two youngest were Teddy Roosevelt and JFK; TR became President via the VP slot due to McKinley being assassinated; And JFK was from a political dynasty, with relatives who were able to get him a head start.
Indeed, political dynasties are common in supposedly representative democracies, and that's a feature, not a bug, from the perspective of those who founded and have since run such systems. The idea that anyone could aspire to the top job is a lie - it's somewhat easier for an unexpected candidate to get in as POTUS or PM than it is for them to become king of a monarchy; But still the top jobs are specifically chosen from an elite group that doesn't include plumbers, electricians, welders, or bricklayers - unless they come up through the trades union movement, in which case they get chosen for their political ability within that movement, not their skill as tradespeople.
Whether this process of ensuring that most people never get any chance of political office is a good or a bad thing is up for debate; But that such a process exists, and does effectively reduce the pool of potential candidates to at most a few thousand (and likely only a few hundred) individuals, is not a matter of opinion, but simply one of observation.