If they couldn't get 5% in 2016, they aren't getting 5%.

Note also that Perot got >5% in 1996, but that did nothing for third party politics. The Reform party doesn't even have name recognition.

You want third parties to be viable? They need to start local and build a base from the ground up. They need to start having significant presence in state politics and legislatures, and we need to see them have a modest bloc of senators and representatives in Congress. Even if a third party did win the presidency, they'd be a complete lame duck with no Congressional support.

You should be asking yourself why third parties aren't doing this, and instead wasting money on presidential elections and conventions. The sad truth is that we don't have a third party because we have no serious third party contenders. None of them want to play the long game to actually win. They'd rather just grift donations.