The lack of Service Centers will bite Tesla in the butt when competitors offer EVs and sell/support them through the dealer networks. Building all the needed Centers will be a very expensive proposition (that I don't see mentioned when people talk of profitability).
The established automakers do not profit from the service departments of their franchised dealerships. In fact, they must pay their dealerships ridiculously inflated amounts for warranty repairs. The situation is quite different for Tesla.
In the case of Tesla, investing in service centers and rangers should be beneficial in attracting customers, even if not direct additions to profits. Break-even for the accounting would be good enough. Right now there is little need to boost demand, but continued growth in service centers and rangers must be long-term considerations to entice new customers.