I'm Miles from the Social Care team at Shopify. Thanks so much for your question.
At the moment, one of the known limits of Shopify Email is we currently don't offer personalisation of emails. It is something we're looking at including in the future though, similar to notification templates using liquid. As this is a known limitation, I've added this feedback to our email team so they know you're looking for this customization.
It's great to hear you're using Shopify Email. How are you finding it so far? If you need any other help with it, check out our handy guide: https://bit.ly/3f0ipXR.
Most ESPs/email marketing platforms will have this built in dynamically. Funnily enough we published a blog on this last month and knowing your customers names is one of the top things to get right.