You could make third parties viable with an alternative electoral system such as Ranked Choice voting.

Replacing First Past The Post voting with an alternative voting system will eliminate any chance of a spoiler effect. People could feel safe in the fact that if the party that best represents them doesn't make it, their vote will continue to be counted throughout the election.

More political parties means more representation, and a bigger portion of the population being involved in the electoral process.

More competition means higher quality representation, even from established parties.

It's part of the real world, and the problem still exists. A solution is still needed. But sure, in day to day life most people better focus on something else!

Currently in California, there is some push at the state level to try and move things along - and override some city rules. Also one surprising city noticed that their past gridlock is not helpful (Berkeley, CA! Surprising because they are said to have invented restrictive zoning).

Then some cities in the Los Angeles area somehow managed to never get in that rut at all, and allow construction. And they are not exactly hellholes because of that.