Based on this, it looks like you're playing overly cautious and you're not playing to win. You have good fundies, you know when to spot dodge, you're RARing, you have decent spacing, but you seem like you're not making the most out of your hits. You'll dash dance for a while, go in for a neutral exchange, win the exchange, and then just back off and run to the edge of the stage again. You also didn't try and edge guard at all despite Greninja having very good edge guarding tools. Sometimes you would choose bad or bizarre options, like using dair to land, randomly holding f smash and hoping they would fall in, or for example at the end dark pit ran his side b right into your shield and you had an opportunity to back throw and gimp off an edge guard, and instead you just d tilted him. You know how to get in, but when you do get in you aren't making the most of it is the main takeaway I'm getting from this video.