In my mind the compacts were designed for the days when computers like these were usually standalone and networking / appletalk was thought of as an addon.
Actually AppleTalk was designed into the Mac from the beginning, something other PC makers never even considered, then again they had slots for such things. So in that regard, Apple was very forward thinking in that they knew they were designing a closed box and would need to provide for some sort of expansion ... Something that is definitely more than any consumer product needed, so they clearly had an eye toward business from the beginning.
And for the money AppleTalk was a very inexpensive solution compared to PC networking of the day (though one can argue it was made up for in the price of the Mac itself). For a time, it was the cheapest, fastest, and not to mention easiest solution on the market, making the Mac very attractive to small businesses. The Achilles heal was that Apple did not have networking software in place when the LocalTalk solution was introduced, nor were there any good hard drive solutions for the networking software that did exist.
However, whether Apple intended compacts to be standalone computers, the success of the Laserwriter in 1985 cemented the importance of networking (which for the next two and half years only existed in compact Mac form), and from the SE era going forward all of the solutions being mentioned here were readily available on the market, easy to come by, and very expensive -- as were all Ethernet solutions available for any platform. Network was not cheap, either inherently due to economies of scale or technologies involved, or artificially so gouging businesses unnecessarily because they could. Either way, AppleTalk remained the least expensive way for ANY Mac (or PC for that matter) to network until file sizes and the number of users became unmanagble, and Apple began building Ethernet capabilities into the Mac, by which time the compact Mac had been discontinued -- and I'm convinced because Gil Amelio had no idea what he was doing or what the market wanted -- think about it, as an entry level computer it was basically an affordable iMac. And for the record, the Color Classic had built-in expansion slot for Ethernet, something only introduced with entry-level computers a couple of years before with the LC.
So I can only assume you mean these solutions are expensive and hard to come by now ... 20 years after the market for them has eviscerated. And in that regard, I agree that sneakernet is the best way to transfer files with the original Macs today,
specifically with the ZIP drive, mainly because Ethernet requires too many intermediaries to be compatible with current Macs, and as you observed, the cost of the vintage equipment which is also hard to come by. And this works with all but the original stock 128K & 512K, for which MacTerminal is the next easiest method directly out of an Modern Mac, described here:
http://mac128.com/Mac128/Mac_128_Update/Entries/2007/8/17_Easily_Transfer_Files_between_a_128K_running_System_1.0_and_OS_X_Tiger_on_an_Intel_Mac%2C_wirelessly!.html