~1960s-1980s: critically important for HIGH SPEED LEASED LINE[0] MAINFRAME[1] MINICOMPUTERS[2] IMPs[3] and PADs[4] (~100-300-1200bps).
1980s-early 1990s: Hayes serial modem AT command set released.[H] Modems critically important for BBSs, UUCP, Amiga/PC warez scenes, early open source distribution. (2400bps/9600bps/14.4/28.8/56k)
~early 1990s: critically important for early internet growth which largely supplants BBSs (56k) and coincides with the initial popularity surge for Linux
~1995-2000: broadband grows rapidly in developed countries. It really kicks the llama's ass. Early P2P warez via Gnutella, MP3 and DivX. CD burning is rife. ISO images are a thing. Against this background, Sony's minidisc fails but accidentally enshrines funny Finns rapping as history.[5]
~1998 winmodem! KK System releases Fax U and popularizes negotiation sounds as art.[6]
~1999: Somebody picks up the phone[7] and the modem connection drops.
~2000-2005: potentially viable but declining option vs broadband (Mbps). Even China had >Mbps HFC broadband at this time. DVDs are mainstream. Steam, Valve's revolutionary harbinger of online software distribution for desktops, is released.
~2004: Artists use modems as current subjects.[8]
~2005-2010: poor countries and extreme desperation only. Physical distribution of software wanes.
~2010: 56k becomes slower than mobile data in most places. Many countries cease hauling copper pair due to mobile plus copper thievery. The developing world comes online without legacy copper infrastructure.
~2013: Artists use modems as retro subjects.[9]
~now = Amusing historical tidbit. Slower than mobile data that's 3 generations old.
[0] https://en.wikipedia.org/wiki/Leased_line [1] https://en.wikipedia.org/wiki/Mainframe_computer [2] https://en.wikipedia.org/wiki/Minicomputer [3] https://en.wikipedia.org/wiki/Interface_Message_Processor [4] https://en.wikipedia.org/wiki/Packet_assembler/disassembler [H] https://en.wikipedia.org/wiki/Hayes_command_set [5] https://www.youtube.com/watch?v=ymNFyxvIdaM [6] https://www.youtube.com/watch?v=MmQSROkTb3c [7] https://www.youtube.com/watch?v=xphxPPQXJKw [8] https://www.youtube.com/watch?v=TJSQILBGoqk [9] https://www.youtube.com/watch?v=cfdZUnHkuuI
Phew. A nice Sunday morning dalliance: back to work :)