I find it incredibly fun, exciting, almost like a gift to the hardcore gaming community. It's one of the few remnants we have left that reminds me of E3 days. I love it.
Marketing in general is really only useful for casual gamers. Hardcore gamers that read forums are plugged in and will hear about something on Gamepass, or from an event, or a shadow drop. If a game is more geared for a hardcore audience then a shadow drop absolutely can make sense. If a game has potential for more broad, mainstream appeal then a larger marketing campaign makes sense. Some people are so disconnected from gaming they will literally see a commercial on TV and that will be the first time they heard of something. I can't imagine that personally, but that's the only type of person worth marketing to. This is why I'm a bit skeptical Oblivion is a shadow drop because it does have broad appeal. I guess we'll see. Something like Hi-Fi Rush is 100% niche and the shadow drop isn't the problem. For hardcore gamers, it does increase hype and good will which is valuable, can increase impulse purchases, and can even skip letting the media and reviews process build the narrative in advance and just get a good game in the hands of players instantly. That also has value if it's a good game.