The amazon listing you provided does not prove your point, all versions of Tomb Raider 1 come with a DOS installer because this is a DOS game. Win95 took a while before it took off for games, even in 1997 a lot of games came with DOS versions on disk or there was no Windows executable at all often. Some memorable ones are: Fallout 1, Oddworld Abe's Oddysey, Atlantis the Lost Tales, MDK, Carmageddon, Dungeon Keeper and many many others. The fact that the CD says it also runs on Windows 95 is solely because Win9x run most DOS programs and games just fine through that OS's DOS Box (unrelated to DOSBox).
The youtube video you posted showcases a fan-made installer for later OSes, such as Windows XP, from 2006 (you can even see it clearly on the modification date). Windows NT based OSes (such as Win2000, XP and all the way up to 10) do not run DOS apps natively, they run them through what is an abstraction layer called NTVDM, in essence a Virtual Machine. Back in the days of Windows 2000 and XP and before the advent of Steam and GOG re-releases such installers were commonplace because they contained a lot of tweaks and extra software/patches to make said games run on an OS they were not designed to run on.
Tomb Raider 1 is a DOS game through and through. The only Windows executable is the ATi Rage version, which has led to it being used to run the game on modern systems at high resolutions through the usage of an ATI 3DCIF wrapper. What you may remember as a Windows installer may have been another game in the series entirely or perhaps some compilation or re-release that did not use it, but the game would have been a DOS exe in any case. I had the Sold-Out version back in ~2003-2004 and it still used a DOS installer although you were presented with a menu in Windows, like with all of Sold Out's releases.