I know several game designers and most develop prototypes using generic components (blank cards with labels, counters, playing pieces from other games, etc) initially and then move onto better components as the game becomes more developed. Some designers will have deals with publishers, others will self publish. In the latter case you often get games with generic components but printed cards/board.
As technology moves on, things become cheaper, and now it seems there is a 3D printer for home use. It is probably in the price range that colour laser printers used to be a few years ago, but like games designers then who opted to buy one, we may well see these 3D printers being similarly bought. The self-publisher can now have a game with nicer pieces – or offer two versions of their game standard with generic components and deluxe with designed pieces. They could well also be used in creating prototypes after initial play test has been done and the game is likely to be published but needs final play testing to tweak rules. Fun times are ahead.