Is a PCB a requirement for an RFM95 family for HopeRF LoRa modules?
The pitch is indeed 2mm (p120 in the datasheet you linked to).

Since RFM95W is not used alone you'd need to put other parts somewhere, so for permanent or repeatable solution it is better to make you own PCB and solder the module to it.

For experiments or one-off designs perfboard is cheap and convenient alternative to custom PCB, and breakouts like those basically work as pitch adapters.

And you are correct, PCB is not necessary. You can put everything in a box, or glue to the wall, or arrange in ikebana on a desk and connect with just about any wire that you can manage to solder. But in any case some soldering is required. Breakout boards like those make soldering easier, not harder.