A friends dad had an old British car, I can’t remember which one it was now, that snapped the timing belt not long after he rebuilt the engine. He put it up for sale the next day, decided he didn’t want to put that much love into something that would destroy itself every time a piece of rubber and cord broke.
Yep, a failure of a piece of rubber and chord should not total an engine, but that’s exactly what you have if you have an interference engine with a drive belt. If that belt fails or just slips for any reason, you can definately kiss your valves goodbye and likely your pistons as well.