Mando is unwilling to ride with a Droid driver. He ends up paying more to get poor service (vehicle in disrepair) from a non-Droid driver. It is cheaper for the firm to provide Droid drivers instead of human drivers, so Mando must pay more for the human driver. This is due to the increase in technology, which increases productivity and allows for an input mix change and Labor/Capital Trade-Off. A Labor/Capital Trade-Off is when a firm chooses to hire capital, such as machines, to replace human labor; this is often seen at the grocery store with the cashier being replaced by a self-checkout.
If we imagine this as two options for hiring workers, it is clear the Droids are being discriminated against. There are cases in this galaxy where people are discriminated against because of their identity, which, of course, harms the individuals who are discriminated against.
The fact that Mando is willing to discriminate against Droids and pay more for an extremely similar service also increases the price he must pay. Discrimination can be costly to the discriminating individuals or firms since they will often willingly spend more money for a less efficient method of production, as Mando is doing with the Droid in this clip, or through a firm refusing to serve a particular group that is decreasing potential revenue. This is similar to sports economics, which sees that teams that have generally racist fans are willing to pay more money for a lesser-skilled player (this is especially prevalent in the Quarterback position in American football). This increase in cost makes the firm less competitive with their pricing and does not allow them to achieve the Minimum Efficient Scale, or the lowest point on a cost curve at which a firm is able to produce a good/service at a competitive price. The Minimum Effective Scale is also the point that allows a firm to achieve economies of scale needed for the most effective competition in their market. Learn more about Discrimination, Labor/Capital Trade-Offs, and Minimum Efficient Scale in this clip!