It’s mostly about performance. Caddy’s Go-based garbage collector starts to negatively impact performance at high load. It looks something like:

server {
    listen 443 ssl http2;
    server_name example.com;

    ssl_certificate     /etc/nginx/ssl/fullchain.pem;
    ssl_certificate_key /etc/nginx/ssl/privkey.pem;

    location / {
        proxy_pass http://localhost:3000/;

        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}