connector not the only issue
If the plan is to get rid of waste then as well as a standardised connector you also need.
1. Detachable cables as standard. I've got a box of micro USB chargers at work, all of our phones are now USB-C. The cables on the chargers are hard wired so they're all waste.
2. Manufacturer replacement program for broken cables. The problem with lightning cables is not so much that they're different it's that they're so flimsy which means that although you start off with a team of 10 people who have one cable each you very quickly end up with 1 working cable between 10. If manufacturers were forced to replace the cables it would encourage them to up the quality.
3. Include other devices, not just phones and tablets but laptops, cameras, headphones, TV dongles, smart watches, wireless keyboards and mice.