Selling Questions (for those who have sold)

If this is in the wrong place, please advise and shut down. So I’m fairly new to collecting Mattel after stopping after Jakks lost the license and it’s brought back a lot of memories and fun, along with the aggravation of hunting. More good than bad so far. However, one of the things me starting this journey was contingent on was selling off a bunch of my older figures. While I’ve bought on eBay before, I’ve never sold anything, and I’m having a lot of difficulty that nobody with customer service can seem to help me with. With that being said, for those who have sold items, what do you guys see as the best market place? Is eBay still where it’s at or are Mercari and FB Marketplace better options? While skimming the boards I’ve seen a lot of complaints from people about selling on eBay, but much like me getting into Jakks, it’s all I ever knew until now. Any opinions and feedback would be awesome, thanks all!