Nothing lasts forever. A few do, however, last for a long time, the best being a few decades, especially in the digital world.

I can guarantee that Netlify [insert other freemium hosting providers] will eventually die sooner than you think.

Honestly I doubt that's the best you can think of. Try harder? Netlify was founded in 2014. That's 10 years ago. They probably won't be around in 2034, let alone 2030. I can almost guarantee it.