What has been the fate of most third parties

Most 3rd parties tend to be ignored.

Explanation:

The reason why they go ignored is because the two party system isn't open to this sort of system in the first place. The two party platform tends to take ideas from third parties to use in their own platform to be able to gain independent voters. Third parties also tend to not fit in the mainstream mindset of voters, however it can raise light to more issues that should be addressed. Most people want to vote for something that can reliably win in an elections, which is why people don't choose to vote third party.