Hi, Welcome to Local Guides Connect.
You haven’t missed anything, Local Guide is a volunteer program and does not guarantee rewards for reaching a certain level.
From time to time, in a selected region, Google may send emails to Local Guides randomly in exchange for such rewards as their contribution to LG, but there are no set criteria or rules for Local Guides to be eligible for any reward.
Have a look at the article below for explanations on how rewards work in Local Guides:
Question about a Local Guides reward email? Read this first
Continue your efforts, and maybe one day you will be rewarded for your contribution.