The electoral college only applies to Presidential elections, but there are many more elections happening for primaries, local, and state elections, where the electoral college doesn't apply. Your vote in these elections is arguably more important than the presidential election and there have been many cases of elections coming down to under a hundred votes.
As for candidates who are insufficient, your vote is not an endorsement of the policies of the candidate, and is an objection to other candidates. This is the flaw of our two party system, and the only optimal strategy is to vote against who you don't want to be president. Voting for representatives who advocate for ranked voting is how this can be fixed, but requires voting in non-presidential elections to create the change, along with a whole set of other challenges.