Some flashcarts give you extra features like save states as well which can be nice.
Overall I’d go with a flashcart any day over real carts with how the market is now. Then again I’m also “all-in” on emulation for the most part as well for ease and convenience. Not parting with my GBA or DS flash carts though, far too useful for when they’re needed.
@Inaminate_Carbon_Rod Not hugely exciting but probably eBay. That or trade in to a local retro games shop, but you'll get most value in your pocket selling directly. Be sure you check for similar game and watches on eBay and make sure you filter to "sold" to get an idea for what they're actually selling for. Ignore listed prices, only refer to sold ones.
@bridgeenjoyer Not an Everdrive but I have a EZ Flash Omega for the GBA but works largely the same. It’s easy to pick the game you want from a list but don’t put 1000s of games on there- that’ll just make it hard to find what you want and you’re not going to play them all anyway.
For the vast majority of games there is zero functional difference between playing an original cart or a flashcart like an Everdrive. You get the original hardware experience without price gauging.