It has a HUGE impact.
The MMM lifestyle is something like 25-30k to live.
If you make 50k.. you can save at most 20-25k, taking (10-15 years to retire, would need to do math).
if you make 200k, you can save 150-175k, reaching retirement in 2-3 years.
The "higher income -> higher lifestyle" is a myth MMM tries hard to dispel. You don't NEED newer cars because you make more money. You don't NEED a bigger house. Sure you can choose those things...