As Lawrenzo mentioned, some types of sites will have a more limited coin loss. If you want more coin finds, especially more dated coins, you have to devote your detecting interests more at Coin Hunting potential locations, such as old resorts, old picnic groves, old recreation areas such as baseball lots, smaller-town holiday gathering sites for outdoor activities such as holidays. July 4th community gatherings and fireworks. Winter fun places like old-time sledding hills and play areas. Vacant lots or fields where they used to get regular circus or carnival activity, and things like that. Relic Hunting sites, unassociated with a bustling old town site, tend to have far fewer coin losses.
Since this is a Relic Hunting Forum, I'd guess the bulk of the 'Relic Hunters' on here spend more time working military battlefields and other similar sites where there was a lot of activity, but it wasn't necessarily the type that generated a lot of coin loss. I have hunted military encampments and fort sites Out West that date to the 1850's to late 1880's, and while buttons, insignia, buckles and all sorts of period artifacts were recovered, there were only incidental coin finds made.
Most of my Relic Hunting that does generate more coin and trade token recoveries, with other interesting artifacts, have been from old town sites that were associated with a lot of early railroad activity, especially those that were major freighting/shipping hubs and drew a lot of people. Of course those with more saloons, billiards parlors, dance halls and the like also were a good draw for the general area ranchers and farmers as well.
So, if you want more old coins, do what all seasoned Relic Hunters do and keep the Discrimination low, use the best search coil, and detector, for the trashy sites, and select the locations that have the better tendency for coin loss.
You ask what do I mean by "our era?" I am referring to our current period in the annals of recreational metal detecting where Coin Hunters can still find coins, but nowhere in the quantities, or old-coin qualities, that we used to find them in the '60s, '70s and '80s. All those decades to centuries of coin loss became periods of coin finds for both newcomers/beginners early on, and more avid detectorists as time went by.
Most new folks to this sport would have a difficult time believing the quantities of coins I used to count out for my Annual Coin Finds. Those numbers are not even attainable today, even with our modern detectors for the simple fact that all the popular sites got thinned out and there hasn't been any old-coin replacement, and with less urban activity at parks and schools, there isn't even much modern coin loss.
Even Relic Hunting sites are very tough to pull good keepers from as they once produced. A day's jaunt to my favorite ghost town in Utah, a 95 to 105 mile trip one-way from where I lived, would usually produce 3 or 4 period coins easily, and better days I went home with 9 to 11 coins. Today, I have to spend a day-long hunt to not be skunked after finding 1, or possibly 2 keeper coins. It's a combination of having the right locations, and appreciating the fact that in the early era of the detecting hobby, there were a lot of coins. In this era, most are gone, and a lot of what remains are masked and that calls for more patience, smaller search coils, and better detectors to work them out of their hiding places.