A lot of games need common image elements. You can find a lot of image assets online or directly from the publisher.
But for common elements such as wooden cubes or discs or meeples or cards, here are some image assets that you can use:
Also check out images below created by Fabian "Viking" Jakobsson under Creative Commons license:
BGA created cards decks PNG image sprites you can use for your games:
(These were created using https://www.me.uk/cards/)
https://x.boardgamearena.net/data/others/cards/FULLREZ_CARDS_DESIGN_COLORED.jpg
https://x.boardgamearena.net/data/others/cards/FULLREZ_CARDS_DESIGN_NORMAL.jpg
https://x.boardgamearena.net/data/others/cards/FULLREZ_CARDS_ORIGINAL_COLORED.jpg
https://x.boardgamearena.net/data/others/cards/FULLREZ_CARDS_ORIGINAL_NORMAL.jpg