Water that’s too pure has a strong affinity to dissolving and/or leaching anything.
In the human body, this can mean that it could pull out nutrients and minerals. Resulting in things like osteoporosis or magnesium deficiencies among other things. For a young and healthy body, probably not an issue. For older or those on the threshold, could be more significant.
There’s no strong better answer here. Is it better to filter out all potential contaminants or risk some of the other potential impacts?
As we have relatively hard water here in SD, I primarily use my RO water source for, coffee makers, clothes iron, steam cleaners, etc. Or if I’m cooking and adding in ingredients anyways. For a glass of water, I generally just use my fridges basic filtered water.