My guess is that Brex is more geared towards Silicon Valley VC funded startups - they look at how much money you have in your bank when setting your credit limit (it’s essentially a charge card if I’m using the terminology right - your credit limit is basically what’s in your bank account). The rewards are also more appealing than this iteration of the Stripe corporate card - 7x rideshare, 4x travel, 3x restaurants. Again, my guess is that Stripe is aimed to businesses that don’t fall into the traditional VC startup model - but maybe the rewards will become enticing enough that they will be competitive with Brex in that area in the future as well.

You also can’t discount Stripe’s Connect API - could see this being used in tandem with that for some interesting ideas

Edit: taking a closer look - they also integrate into services like Expensify and if you use their card, first $50k of payment processing is free so that’s also interesting. If you’re paying sticker price, that comes out to something like $1500