Re: "Free Travel Insurance": Insurance policies have constraints and limitations of cover, normally as some situations mean higher risks.
eg Altitude. You are more likely to suffer medical issues at higher altitude and more likely to require emergency services. Once you've seen people suffer bad altitude sickness you'll appreciate the potential risks. In the UK most travel insurance policies restrict altitude to limits most tourists wont experience. But go to South America eg Peru & Bolivia and some of the really amazing places are above insurance cover limits so to maintain cover you need to pay for a better policy.
Visit La Paz and you might want to cycle the Yungas Road North (which is a truly memorable cycle ride but high(er) risk) - that means high altitude and mountain biking both excluded by most "standard" policies so you'll need a more specialist policy or paid add-kn cover.
Or you could look to save and just skip such places.
nb It's not free. You're just fooling yourself if you think these cards are giving away something for nothing. You are paying through charges the card company is getting. Don't fall for marketing ploys.
Ian