Sports games are more collectible than any other genre. It's also the oldest and most popular video game genre and the games age much more gracefully than most genres, as sports games continue to move further and further away from the "game" aspect.
The mythology of sports games in general, or even individual sports, are infinitely larger than other game genres, with a limitless roster of characters, stories, events, systems, stats, etc. It's so big that even if you don't touch anything before the current year, you still won't have the time to give every game the attention they deserve. Fortunately, there is so much flexibility for areas to focus on. Whether you decide to stick to a particular console general, sports, time period, fictional or licensed, fantasy/sci-fi, adventure/RPG, management, etc.
The infinite mytholgy gives you endless subject matter for fan art, fan fiction, tribute videos, etc. So if you begin working on a fan site, you'll never run out of inspiration for content and there is a huge non-video game fan base who will still be interested in many of your projects.
In the end of course, it doesn't matter how collectible your interest is over other ones, only that you are investing your time and energy into what you are truly passionate about.
However, if someone else isn't interested in collecting and is instead only looking for financial investments, sports video games are still video games and therefore a terrible investment.