Service/saas: help people set up TikTok shop. TikTok made it super confusing, you could learn how to do it, see if demand is there, then train up cheap labor on fiverr and outsource it. Eventually scale to an agency that specializes in TikTok shop/product management
Manufacturing saas: find some manufacturers on Alibaba that make good customizeable products and then pay a developer to build an automated quote tool for them. Market the tool and take a cut off every deal. The customer never has to wait for a quote and can buy on the spot without any correspondence. I.e. high quality gift boxes for people’s packaging who are selling on Amazon and Etsy. The American services that are affordable (boxgenie, packoka, packlane) have a shittier quality product and longer lead times than China on average (I do a lot of manufacturing).
Sell products supporting home agriculture on Amazon. Mushroom cultivation, micro greens, grow kits for trendy vegetables etc. Start with one unique product and then cater to the audience you build
A few ideas I’ve had recently: