This is what happens with my open source Chrome extension's reviews on the Chrome Web Store. Not that you can really make money off of extensions even if I wanted to, but such is life.
- $100k with a browser extension: https://www.indiehackers.com/post/css-scan-made-over-100k-d6...
- $38k/month with a browser extension: https://www.indiehackers.com/podcast/187-jordan-oconnor-of-c...
- $3.1k/month with a browser extension: https://www.indiehackers.com/product/night-eye
- $2.5k/month with a browser extension: https://www.indiehackers.com/interview/weather-extension-ad9...
Why not? There's successful projects selling or based around extensions.