Looking for some e-commerce ideas

I opened an ethnic apparel e-store as a part time gig. It did pretty well the 1st year with ~$20k revenue and with around 30% profit margin. Honestly I was expecting it to fail the first year. The 2nd year was a disaster as I couldn't spend much time on it due to other personal obligations so the sales were minimal. I know if I can spend more time on it, I can continue to grow the business. However, I feel like this one has ran its course and want to pivot to something new.

I am pretty good a making websites, streamlining/automating my workflow, and marketing the product on social media (90% sales came from here). I have great sense for design beautiful products (Manufacturing and Mechanical Engineering background). So I am confident I can handle all the admin work that comes with a new e-commerce business.

I am looking for new e-commerce ideas that are niche and not easily replicated by Behemoths like Amazon and Walmart. I have few in mind but want to know what y'all think.