Does the rationale of the path of least resistance conflict with the challenges of life that are required for change?

No:

"Life provides enough problems without us making more."

Yes:

• If you're up to your neck in water, (maybe) it's time to stop walking, and start swimming.
• If you don't have enough challenges you can make what you're doing more difficult - or go find something better (harder) to do.
• Imagine you are at the beach. If you swim out far enough, you can surf back in. If you get caught in a rip tide/rip current, the current may be too strong to fight.*
• Metaphorically, just because you're going in the direction of the current doesn't mean you have to just stay afloat** - you can swim.

* - swim perpendicular to the beach, then go back in.

** This behavior also seems characteristic of something having gone wrong. (If this is the case, identifying and addressing the problem may be as important as trying to change tack - which is not a 1d move in the literal world.)