For my money though, comparing SaaS and deployed platforms is a bit too big of an ask. Comparing Apples with Apples is a good ambition but by their nature you have two very different types of fruit there. Magento site performance, for example, is almost entirely dependent on how well set up the store is. A good Magento developer can make it sing – but it takes time and expertise…. As a SasS solution the variance between Shopify sites should be much smaller.
If you update a Subscription product price from $100 to $120, all those Subscriptions created at $100 are not updated to $120. You have to manually go to EACH subscription and update the price which is very time consuming when you have hundreds or thousands of subscriptions. There should be a bulk way to update all subscriptions pricing without having to go one-by-one through each active subscription.