westfw:
You can still download the old IDEs with their "examples", most of the 3rd party libraries are in source-controlled repositories like github (the IDE too, actually), and the forums are delightfully (?) un-purged, so I'm not sure it's as bad as you think.
Actually, no, you can't.
If you go to the Software, Downloads section then look for previous IDEs they jump from 1.6.13 to 1.8.0.
What the hell happened to the numerous releases of 1.7?
They exist! I know they do as I downloaded 1.7.6 and 1.7.10 when they WERE available. They contain some very useful and practical examples including working examples for the Ethernet2 library which work on the LeonardoETH.
I know, I installed 1.7.10 on a an ancient Acer TravelMate 2490 (labelled as 4250 - I HATE it when manufacturers do that) laptop running Windows 10 Pro and this morning plugged in my LeonardoETH, set the board type and COM port, opened the DHCPAddressPrinter example from the Ethernet2 examples, built and uploaded it and BINGO - worked first time.
Try that with 1.8.5 and your in trouble. All those examples - GONE!
When I first tried 1.8.x (can't remember precisely which subversion) with one of my UNO R3's fitted with the offical GSM V2 shield, none of the examples would even build. They threw up shed loads of compile errors. Try exactly the same examples under 1.7.6 and they built, uploaded and (after sorting out an issue with the auto-power on for the GSM modem) worked first time.
All versions of 1.7.x of the IDE have been redacted from history.
This to me, and I've seen it a LOT with PC hardware, looks very suspiciously like attempting to kill off (by making them useless or very hard to use) retired products to get people to buy new.