I have a Beryl AX (GL-MT3000) and had similar issues. Although ping is often dictated by the server distance (e.g., connecting from Europe to the US results in higher ping compared to connecting within Europe), there are ways to improve your speed.
For the speed issue, it depends on your provider, but I couldn't get more than 70% of my actual download speed until I changed the MTU to 1280 in the VPN configuration. Here's how you can do it:
Access the VPN Dashboard: Connect to your Wireguard Client.
Change the MTU Value: Click on the Options icon, and change the MTU value to 1280.
This change is config-specific, so you'll need to redo it if you switch locations. Note: once changed, you can't reset MTU to blank without deleting and recreating the config.
Disclaimer: This helped me, but it might not work for everyone.