Yes, Hanno, it is one of the benefits of the web that museums and archival institutions have scanned and made available so much primary source material. For which I am very grateful, of course.
I can sit at my desk in our nice comfy home in Colbert WA USA, and quickly and easily look at a vehicle ARN in the original Australian Army vehicle register on the AWM site in Canberra, Australia, or search through the personnel dossier of an Australian who served in the First World War on the National Archives of Australia website or look at scanned documents on a host of other topics in a variety of other places.
There are also many non-government/private sites such as REMLR, MLU and many others that provide a wealth of scanned documents put up by individual members.
Still, there is a lot more that is
not scanned and available in an on-line search, so researching any particular topic in depth usually takes time at a desk somewhere, leafing through original documents. And with the cost of obtaining files that are not yet digitised, it is sometimes cheaper in the long run to travel to the location than to order on-line, particularly for research projects involving large numbers of files. Looking at, say, 500 files at an average cost of $60AUD per file for a copy/digitized from the National Archives = $30,000! Copy rates from the UK and NZ archives are no better.
Cheaper/more cost-effective to travel there and go through the files on-site, and enjoy the 'holiday'!
We are well away from this thread's Polsten mounts on 15 cwt trucks, but it is an interesting diversion nevertheless.
Mike