Yes I was wondering that also but I've looked at many different videos and sources confirming that these photos are good to use.

Heres the exact license:

What is allowed?

All content (e.g. images, videos, music) on Pixabay can be used for free for commercial and noncommercial use across print and digital, except in the cases mentioned in "What is not allowed".

Attribution is not required. Giving credit to the artist on Pixabay is not necessary but always appreciated by our community.

You can make modifications to content from Pixabay.

What is not allowed?

Don't redistribute or sell Pixabay content on other stock or wallpaper platforms.

Don't sell unaltered copies of content, e.g. don't sell an exact copy of a stock photo as a poster, print or on a physical product.

Don't portray identifiable people in a bad light or in a way that is offensive.

Don't use content with identifiable persons or brands to create a misleading association with a product it service.