I have been drinking natural unfiltered raw water straight from rivers, streams, springs and ponds and I haven’t ever gotten sick from it. I strongly believe and know it in my heart that water from springs, rivers, streams and ponds is cleaner and better for you than tap water and filtered processed water that we get which isn’t natural water. If I’ve never gotten sick from it than it’s okay right?
It all depends where you are and how carefully you choose your water sources. In the Malaysian jungle (peninsular Malaya and Sarawak), I used natural water sources all the time for years on end without ill consequences. There are numerous springs and small streams where the water is always good, but we never used a main river where there was habitation upstream. On rare occasions we used a wild pig wallow, provided the water was crystal clear. On even rarer occasions I have used natural water sources when camping in the British countryside, where even more care is required. One never knows what chemicals may have got into the run off, though up in the hills it is safer.
You may have a very good immune system, but not all people have. Usually I used natural water sources when there was no other choice, but in an inhabited area I would choose tap water if it was easily obtainable. It is the opinion of the medical profession that tap water is just as good for you as natural water, and carries less risk.