I used to think where there's more people there exist more customers, but don't forget that for every so many thousand population, there are so many more landscapers too.
In a city like where I live, population 500,000
We have well over 400 landscape companies.
Which averages out to one landscaper for every 1,250 population.
The math may not be exact for every situation, but I guarantee ...
The higher the population, the more landscape companies competing.
Live in a small town with a population of say 25,000, you have 20 landscape companies.
It all averages out in the end, you won't have more customers just because there's more people.
Do a good job, and let word of mouth get you there.