No politician "owns" your vote. You do.
Back in 2008, Barack Obama became the first Democrat to win the state of Indiana since 1964. Obama defeated John McCain by a margin of 26,163 votes. Former Republican Congressman Bob Barr got 29,186 votes. This year, the Libertarian candidate's vote total was bigger than Joe Biden's margin of victory over Donald Trump in key states, leading Republicans to again complain about Libertarians.
As a three time former candidate for elective office, let me make this very clear: No candidate owns your vote. This is true even if you are part of one of the two major political parties. If you cannot vote for your party's candidate for whatever reason, then you are not obligated to do so. You should instead vote your conscience. As an adult over the age of 18, you own your vote.
The Republican Party took a libertarian turn in 2010, and some of the Republicans elected to Congress in that election and the next two elections did genuinely attempt to cut spending. However, the party as a whole did not do enough. Once Donald Trump took office, the Republicans controlled both the legislative and executive branches and showed no fiscal discipline whatsoever. Trump himself was hesitant to support criminal justice reform, a key issue for libertarians.
So the formula here is pretty simple. If you want to win libertarian voters, you should actually make a serious effort to limit the size of government. Perhaps you could even work to return authority to the states instead of looking for a federal solution to problems. It is simply not enough to point to the Democrats and argue that they would make government bigger than you would. Enough libertarian voters said this with their votes: "Fool me once, shame on... shame on you. Fool me, you can't get fooled again."