Hi,
Magento powers 30% of all online stores on www and you can safely say those are not all small stores while most of them are running a Community edition. We have clients getting hundreds of orders a day running on Magento Community. Come to LA for Magento IMAGINE 2017 in April and you will see for yourself and meet the big and small Magento users.
It's just a matter of a quality design and properly setup hosting and you can dump thousands of visitors into your store without any issues. And the number of extensions and integrations available for Magento is unmatched by any other system - just make sure you take it easy on the extensions and get them only from quality providers and you'll be fine.