For most folks, focusing on doing your full time job well and getting promoted/finding a better paying job is _significantly_ less effort than starting a side hustle that pays you meaningful money.
That being said, if you feel like grinding and learning a lot about sales and marketing, consider launching an app in a marketplace (Shopify/Airtable/App store/Play store, etc) to get started (hell of a lot easier than starting a SaaS, ask me how I know).
That being said, if you feel like grinding and learning a lot about sales and marketing, consider launching an app in a marketplace (Shopify/Airtable/App store/Play store, etc) to get started (hell of a lot easier than starting a SaaS, ask me how I know).