why we don't have jumpdrives from the beginning?

[Tachyon]

The best possible way to describe the lack of jump drives is probably to say this: Jump drives require fuel. Jump gates don't. Having jump drives would make flights much more expensive and trade less lucrative due to the need for additional fuel. Having jump gates makes things more efficient since all that extra space that would be needed for fuel can now be converted into cargo space, making trade more profitable. The extra efficiency of jump gates probably led to jump drives becoming obsolete.

Freelancer and Disco never made sense. Thank you for asking though.

This and that explains everything

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