Start with the server, not the plugin
No caching plugin can fix 400ms of network latency. If your audience is in Bangladesh, hosting in Dhaka removes more milliseconds than every optimisation plugin combined.
Use LSCache, not a PHP cache plugin
If your host runs LiteSpeed, install LiteSpeed Cache and delete W3 Total Cache or WP Super Cache. LSCache operates at the server level, so a cached page never touches PHP at all.
Compress images properly
Bengali e-commerce sites routinely ship 2 MB product photos. Convert to WebP and cap the longest edge at 1600px. This alone often halves page weight.
Load Bengali fonts locally
Google Fonts adds a third-party DNS lookup and TLS handshake. Self-host your Bengali font (Noto Sans Bengali, Hind Siliguri) and use font-display: swap.
Measure on a real phone, on real mobile data
Lighthouse on your office wifi lies. Test on a mid-range Android over 4G in the evening, when the network is congested — that is your actual customer.