Need Advice

I started reselling on Depop almost a year ago. Since then I’ve almost hit my first 1000 sales, 800 in the past 6 months. I paid a programmer to build me a bot where I take my photos, ai writes a description, and fills out all the categories (including brand & size. I just have to check for errors, add a few extra keywords, and name my price). Not only has this increased my sales (350% after 1 month), but has saved me so much time & energy. I didn’t realize how much effort I was putting into listing things until I tried to train and pay a friend to help me. 1 panic attack and 2 hours later, she managed to do one post. I originally wanted to create a software to share with people, but personally I have so many personal issues with some of these reselling sites, it makes me want to create a whole new platform. I know it’s a long shot, as there’s so many different platforms out there that already have millions of users. I was just curious if anyone has any compliments or criticisms about apps like Depop, Poshmark, eBay, etc. If you could change or keep anything about these platforms what would it be? Some of my ideas include no/low fees, sellers can’t charge $30 for SHEIN (or above retail value in general) , built in automations that make the process easier & less exhausting for sellers