When it comes to editing videos for social media, there are a ton of ways to do this.
One of the most important factors in the right NLE is the type of content and where the content is coming from. If you are editing a piece with lots of talking generally you will need a desktop based NLE so that you can zoom in on audio files to make good clean cuts. Mobile NLEs are great for visual only content, but in my experience fall short when you are editing speaking pieces.
For visual only pieces, my favorite NLE is iMovie for iOS and KineMaster for Android. These are great tools for anything visual based. Adobe Rush is close, but I have found it to be a bit more klunky as far as performance goes. I think iMovie and KineMaster are tuned much better for performance on a phone at this point.
For editing content that involves speaking heads and cutting audio, I still think this requires a desktop NLE. This opens up a ton of options. If you're a marketer and not a video editor by trade, Headliner Pro is a very functional NLE and is 100% web based. If you're a professional video editor than you probably have your own opinion. That said, I will give special not to Blackmagic's Davinci Resolve. It really seems to shine right now in a great balance between features & simplicity, and seems to take great use of both Mac & PC hardware. It also helps that Resolve is a free application, pretty unreal.
That said, there are so many great options, the NLE you choose has much less to do with 'best' and much more to do with what you prefer.