Generally replica watches are worn by people who seek the status of a watch rather than having an appreciation for horology, thus vain weirdos. Poor replicas are just sad. But there are some very, very high quality replicas out there that you can appreciate the effort of at the least. A factory recently produced a clone of the Rolex 4130 Chronograph movement and started produced functioning Daytona replicas. That is very interesting considering the price point is still around $600 USD for a decent, Chinese chronograph that is hand-built.
There are obvious differences between a genuine and replica watch, however. Some people who own many Rolexs purchase replicas for fun, or super high quality replicas so that they don't risk wearing their real watch somewhere they'd lose it or have it stolen. Someone who doesn't necessarily use their watch and just wears it for attention or vanity wouldn't care if their Submariner is as durable, shock-resistant, or reliable without needing a service for 10+ years. The build quality, materials, and engineering that goes into a $7,500 Genuine Submariner compared to a $500 super replica is huge. While it may pass in the looks department when observing the bezel, case, weight, crystal, dial, printing, etc., the movement is where it really counts. Replica watches have a myriad of issues though, as they are almost always Chinese clones of ETA movements styled link genuine movements. They are not built by formally trained watchmakers though, so they have a high defect rate and generally poor quality control. Additionally, the actual durability of the Genuine watch is higher than the replica - even though they present themselves near identical. Richard Hammond's Rolex Submariner 16610 survive the crash and following car fire that absolutely destroyed the Rimac he was driving - working.
Consensus:
-Crappy Rolex Replica: Pitiful, not worth anyone's time - for someone who has no idea what they're doing and is desperate for attention
-Super Rolex Replica: Acceptable visually, not reliable - for someone who only cares about the "look", generally NOT a fan of horology
-Genuine: No substitute for the quality of the real thing
It's really a shame these watches have gone from high-quality tools to luxury items over the last couple of decades. Brings an entirely undesirable type of people into the community.