Low power ebikes should be allowed on trails.

This 100%. And the trend is moving in this direction, if this news from a while back is any indication. There, the US Forest Service made the following conclusions for Tahoe National Forest:

Class 1 e-bikes are similar to traditional mountain bikes in terms of components, relative speeds and impacts to trails.

And:

The inclusion of Class 1 e-bikes as an approved use on the trail expands access to individuals that may not be able to walk or ride a traditional bicycle as far or long.