How are radio telescopes and mars rovers in my interest? How would you know what is in my interest? I worked for my money so the person in the best position to judge what is in my interest is me. I am sorry for you if that is such a hard concept to understand.
So you think we shouldn't try to understand the world around us?
Frankly, your particular interest is completely irrelevant.
Scientific research is of societal interest, even if your particular interest differ. The best you can do is vote for parties that promise to shut down scientific research, or find another group of likeminded morons and form such a party with them.
If you disagree with the concept of taxes, well, sucks to be you. May your desires never come to fruition, because life would be hell.
It would be great if we had line-item vetoes on our tax forms. However, we don't. You have to fund some things you don't like or agree with, and so do I, and so do the rest of the taxpayers.
That's just how taxes work. Like capitalism and democracy, taxes suck, but nobody has come up with adequate substitutes that check all the necessary boxes.
Why wouldn't I veto everything except the give me back my money tax? Now, I'm not actually ridiculously selfish asshole that doesn't think of others or the long term consequences of my choices, but it's a prisoners dilemma, with everybody else in your country, and defecting gives you money back. Cynically I don't think that'll work.
You’re free to vote towards your goals, or move to countries which invest basically nothing in research. There’s plenty of them. I suspect you may not enjoy such great quality of life there.
In case it wasn’t a rhetorical question, they’re in your interest because through the process of building them we improve our understanding of the world, develop new technologies which the industrial system wouldn’t have backed, educate the next generation of engineers and scientists, and inspire the kids that will form the second next generation.
Private research already exists and works well in some fields, mine included. But public research is just as important since it can afford higher risk and longer scope. You can’t begin to count the startups that were created as spin-offs of university research groups.