BigCommerce ships with a lot more features for B2B and enterprise out of the box, than Shopify.

To get a Shopify store configured to the B2B & enterprise features of BigCommerce you need a fair amount of 3rd party apps, bubblegum and duct tape

Actually if you want a serious B2B tool set Shopify wants you to get ShopifyPlus thats 2000 per month, 12 months upfront and no free trial.

I love Shopify and Shopify Plus, have worked with their team very closely on many large re-platform projects and I have to say for B2B it is getting there, very slowly, but still miles away from being B2B enterprise-ready without a significant amount of custom build work, hacks, apps and workarounds.

There are so many issues with Shopify Plus for B2B use cases that it's hard to recommend unless the store is very simplistic.

If you're looking for a more in depth answer, I explained it here: https://www.logicinbound.com/bigcommerce-vs-shopify-reviews-...

Make your font color darker.

They each have their pros and cons. Meats and potatoes, they are basically the same, but each one has features that make one better than the other.