From the about page:

Our goal: to enable you to harness the creativity, beauty, and power of creating your own web site. To rebuild the web we lost to automation and monotony, and make it fun again.

Neocities is:

• Helping the web. We are here to empower people to develop independent, creative sites.
• Free. We will always have a free web site option.
• Open source. Neocities believes in open source, and we share code back with the community.
• Not an advertising company. We’ll never put ads or watermarks on sites, and we don’t sell your data to marketers.
• Anti lock-in. Easy site downloading, and support for custom domains.
• Sustainable. We want to grow, but that growth cannot risk the site (or compromise our principles).