How can sales enablement improve the employee experience and help retain talent? Any guidance would be great!

I'll start by saying that the activity depends on where the employee is in their journey.  If they are a new hire, the employee experience and retention activities are different from a more seasoned employee who may be looking to grow within the organization.  

Here's an example of what we do for new hires.  We have a relatively small sales team (~200) so we can take a pretty personal approach.   This may not be viable for bigger organizations.  For new employees, our onboarding is done almost 1:1 because of our size and global hiring practices (we aren't hiring tens of salespeople in the same region at time).  That means when a new sales hire joins, our Sales Enablement team walks them through the different steps 1:1.  These sessions could be platform-related training or introductions to key process owners (PM, Sales Ops, compensation, etc.).   
We started this 1:1 model about 18-months ago and have received really positive feedback.   The new hires feel supported by our team.  And because we are making 1:1 introduction to cross-functional leaders they know they will get the necessary support on their deals when needed in the future.   We also use a continuous improvement model where we ask the new hires what they would have liked to do differently or what great experiences have they had from prior companies.     

Just a few examples.  Happy to connect if you would like to discuss in further detail.

It's really important to understand your employees "why". Why are they doing what they're doing and what's their end goal? If they want to move on or grow their career, a lack of enablement will have them running out the door to somewhere else, where they will.

If somebody wants to stick in their current position, continuing to help them improve in that role is what prevents them from being bored/stagnant