It’s not easy to know in advance when your timing belt is going to break. When your timing belt does break, will it cause extra damage, or just leave you stranded?
On some engines with interference valve configuration, the valves and piston share the same space. They never connect unless the timing belt skips or breaks. If that happens you can spend a lot of money for ancillary damages.
Some timing belts are chains. In general, timing belts should be replaced or adjusted every 50,000 to 70,000 miles. If a timing belt is loose or worn, then it could slip and change the valve timing.
If that happens your vehicle performance could be affected, the engine might not start, or engine damage could occur. Check your vehicle recommended maintenance schedule.