I can counter-recommend Kenney's game assets, it's got sprites, buildings, terrain, backgrounds, top-down, side-on, isometric... Lots of variety for different genres and settings, too.

https://kenney.itch.io/kenney-game-assets

Remarkable, they're licensed CC0 https://kenney.nl/support

I always wondered why art is never licensed like software. There is a plethora of free software but I thought very little similarly licensed art. In fact, I think it's just that I wasn't looking. There's lots of it around.

Thank you for sharing.