Shopify is one of the best ecommerce platforms in terms of load speed, this being confirmed by lots of independent studies. Even so, every day somebody is complaining on Facebook groups or in Shopify’s forum about the load speed.
Load speed is extremely important for ecommerce, there’s no question about that.
Say you install 5 apps on your storefront. When a customer arrives on your store, there are 5 requests made to 5 different servers around the globe. Each request means a set of connections (handshakes) that take a bit of time to exchange information — and each app, depending on how well it’s built, might make more requests to download content, script files, images. Although browsers are able to parallelize requests, depending on how well apps are built and how well their servers respond, it might take a while until your store is fully loaded.