Here are some of the differences:
Studiocart is a shopping cart-based solution, which, typically, is advantageous if you have an e-commerce store with 100s of products. Mango is not a cart-based solution. What that means is that Mango does not force you to create the actual checkout page, but leave it to the pro's (in my case Stripe & PayPal). The reason is that they continuously optimize for conversion, mobile compatibility and speed. Something most cannot achieve when building it themselves. Instead your focus is around building the actual flow you want people to go through to optimize for increase order values.
Studiocart heavily prefers you to use Elementor. Mango allows you to use ANY WP editor or WP theme to build your actual sales funnels and sequences. This is an extremely important point for me, because I wanted to have flexibility - what happens if I need to change my WP theme or WP editor tomorrow? With Mango you can easily adapt in just a few clicks.
Studiocart is based on "templates". Mango does not provide any page templates. That is done on purpose so you can use any page design, theme or editor to create your sales pages. Mango will work with all of them. (The actual checkout page is provided & continuously optimized for conversion by Stripe or PayPal as previously mentioned.)
Studiocart does not appear to provide any advanced sales flow sequence options. That is, you cannot branch into multiple paths even mid-funnel based on customer purchase behavior. With Mango you can.
Studiocart does not appear to enable you to automatically upgrade / change customer subscriptions mid-flow. For example, a very popular up-sell flow is to switch a customer's subscriptions to a higher tier on a subsequent step and then do that automatically while also removing the previous subscription without lifting a finger. With Mango you can.
I am sure there are amazing features offered by Studiocart that Mango may not offer, but part of the reason is that I wanted to keep it lightweight and simple.
