In general, you can use Esri Leaflet with modern browsers that support fetch and ES2017.
Below is a specific list of supported versions:
- Chrome 96+
- Edge 96+
- Firefox 97+
- Firefox 91 (ESR)
- iOS Safari 14+
- Safari 14+
Esri Leaflet Vector utilizes WebGL to display vector tile layers. A graphics card with WebGL support and a compatible browser are required. To test whether your browser supports WebGL, go to get.webgl.org.