Well, you could, but it would not change the status quo. At most, a strong showing by a 3rd party candidate would force the losing major party to adjust their platform. For example, if Kennedy pulls a strong 3rd this election, the losing party would look at Kennedy voters and adjust their platform so that next time they will have those voters on their side.
The only way I see of a new party winning major elections is as a split from one of the two major parties. For example, if the GOP changed their rules and nominated Nikki Haley, Trump then forms his own MAGA party and runs under the MAGA ticket. Several of the losers of the Republican Primaries in state races decide to do the same, and should Trump win, the mainstream Republican party then becomes the 3rd party until they die out.
Our winner-take-all style of government discourages the emergence of viable 3rd parties.
