difference between OptikTV 2.0 vs OptikTV 3.0?

I've never heard of OptikTV 2.0 or 3.0. There is just Optik TV which is likely to be renamed TelusTV+ at some point soon. PikTV no longer exists so the Core plan under Optik is its replacement. Have you looked at Telus's website or the channel guide for the available channels?

The "Essentials" is being renamed to Core as listed in the channel guide PDF and the bundle selector.