There are some logistical reasons, too

Trader Joe's has made it clear that its brand revolves around customers enjoying the in-store experience, but it has also expressed reluctance to tackle the complexities of establishing a delivery service. During a recent podcast, a marketing executive from Trader Joe's noted that implementing delivery would necessitate a significant investment of time and resources to create an online ordering system and develop a new transportation network for home deliveries. While many supermarkets have successfully adopted delivery services, Trader Joe's executives believe that doing so would lead to higher prices for their products. Additionally, many customers expect free delivery, which would prevent the company from passing on delivery costs. Instead, Trader Joe's has chosen to focus on investing in its employees to maintain its high-quality in-store experience. Although the future is unpredictable, it appears that Trader Joe's is committed to avoiding delivery services, especially since the company managed to navigate the challenges of COVID-19 without venturing into that area and has been characterized by business experts as cautious about change.
But there are workarounds for getting Trader Joe's delivered

Trader Joe's maintains a strict no-delivery policy, which means it doesn't partner with third-party apps like Instacart for delivery services. However, if you're determined to have those spice blends or cauliflower gnocchi delivered to your home, there are ways to work around this policy. One effective method is to use apps like TaskRabbit or Dumpling. Essentially, you're hiring someone to shop for you at the store. This approach may not be the most efficient, as these apps typically lack real-time inventory for your local Trader Joe's, leading to some uncertainty about product availability. Additionally, you'll usually pay these shoppers by the hour, so if you spend a lot of time discussing unavailable items, your costs could add up.
You can also find some Trader Joe's products on various online retail sites, such as Amazon and Walmart. However, don't expect to fill your cart with a full range of groceries this way; for instance, Walmart primarily stocks the signature herbs and spices. Be prepared for higher prices, as these items are often listed by individuals who bought them at Trader Joe's and are reselling them at a markup. Still, if you're only looking for a few specific items and don't have a Trader Joe's nearby, this could be a viable option.
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