Yes, it’s completely safe to uninstall Avast, but doing so will leave your computer unprotected from potential security threats. I strongly recommend installing another antivirus as soon as you’ve uninstalled Avast.
There are many good Avast alternatives, but Norton 360 is my favorite — it’s capable of detecting all forms of malware (both known and new) and comes with a lot of other top-quality features like dark web monitoring, email protection, identity theft protection, parental controls, a VPN, and much more, all designed to keep you completely safe online. It’s also very easy to install and use, and offers multiple affordable plans to suit different kinds of users.