Greater line weight does help for stronger wind but does not mean that it will cast farther than a lower line weight. It is easier to cast a 5wt. in stronger wind than a 3wt. for instance but both should be able to cast equal distance with little or no wind force. If your rod is rated for a 3/4wt. then it should cast either of those lines equally well. Some folks like the greater line weight of the two line rating so that the rod loads faster. By the same token but against the manufacturer's rod rating, some folks like to use one line weight higher than what the rating is for the rod so that the rod will load the line even faster for a faster cast but it also can overstress the rod and to me is not a good idea. It is best to use the manufacturer's line ratings on the rod rather than risk damage to the rod. Lines come in types. For instance, a WF type is a weight forward and helps with casting larger flies and may respond better in stronger wind since the weight of the line is forward in the tip section. A DT type or double taper helps with casting lighter flies like dry flies and is used for quieter presentations for spooky fish but would be a poor choice in strong wind since the weight of the line is in the midsection (tapered at the both ends). A L type or level line has its weight equally distributed throughout the line or leveled and is supposed to be an all purpose line but in reality has deficiencies for both of the above line types, being neither able to handle large flies or able to present lighter flies quietly. But the level line can be used where neither of those deficiencies are important (medium to small flies for less spooky fish). At least this is my take and experience on standard line types and they all have their place and purpose. There are also specialized types beyond the standard types, like Bass Bug Taper, Steelhead Taper, Pike Taper, Saltwater Taper, Bonefish Taper, Tarpon Taper, Redfish Taper, etc.
Then there are shooting heads, intermediate lines, sinking lines, sink tips, and so on. I don't want to get into the subsurface lines. Like the different floating lines and types, they all have their place for different situations, purposes, and preferences.