Maybe it's a cultural shift, that is, people can get information about a game - reviews, etc - a lot more and easier than back then when you depended on just the right issue of gaming magazines. Alternatively, the best you had was looking at the back of a game's box to get the gist of it.

But with shareware you often went in blind, especially once CD-ROMs became a thing (attached to magazines) with dozens if not hundreds of shareware games and applications. The culture was one of browsing and trying stuff out.

Nowadays it's more about being able to build up hype and brand / name awareness over time, with peak moments being e.g. the E3 conference. More recent even is streaming on Twitch and let's plays on youtube, allowing people to see the game before buying it themselves. And of course there's free-to-play or low cost games with in game purchases and/or live services.