They certainly can be, depending on the scope of each game; writing, art, playtesting, etc. aren't necessarily cheaper just because the result is being printed in a book, at least not if you're paying everyone involved a living wage. It's tough to judge that based on Kickstarter funding targets alone, though, for a couple of big reasons:
Both crowdfunded video games and crowdfunded tabletop RPGs are rife with personal passion projects where the lead developer(s) is/are essentially working for free; however, for a variety of reasons, independently published tabletop RPGs are more likely to be produced by people who actually depend on their game design work for income, which is going to result in targets that look inflated compared to projects whose principals are donating their time.
Crowdfunded video games often hugely lowball their initial targets, either because the "real" goal is hidden in the stretch ladder, or because they're using the campaign as a consumer interest poll, anticipating that doing well on Kickstarter will help them secure the game's real funding from publishers or investors. You know how some video game crowdfunding campaigns will easily blow past their basic target, then cancel the campaign at the last minute anyway for nebulously defined reasons? More often than not, this is why.
The upshot is that, while both crowdfunded video games and crowdfunded tabletop RPGs are often guilty of artificially deflating their public-facing funding goals, crowdfunded video games tend to do so both more severely and more often, which gives people funny ideas about how expensive video games are to develop.