There are a lot of consulting services exclusively focused on building for Outsystems, Mendix, Webflow, Bubble, Zapier, Wix.com, IBM Apex, Appsheet, and Shopify platforms.
The number of entrepreneurs building on low code/no code platforms probably runs into hundred of thousands. Maybe even more if you count the consulting businesses built for the Salesforce Lightning platform.
I run an open source low code platform to build internal apps called Appsmith[0]. We know dozens of consulting companies who've built Appsmith apps for their clients. I bet every fast growing low code/no code product has small businesses built on it because the tech consulting market is just so huge.