My first business that used Stripe was with them from their early days in the UK, and my recollection is very different to yours. They were potentially a bit more expensive in terms of fees than getting a separate merchant account and payment gateway set up, but not hugely so and at least they were consistent and transparent about those fees.
Moreover, they were vastly different in terms of the ease of integration. To take card payments via the traditional big banks and other established services, you didn't just have to put up with awful APIs and worse documentation, you also had to put up with onerous application processes that could take days to collect the required information to apply, then weeks to approve (or not), and even then often imposed severe restrictions for businesses with no trading history up to and including piercing agreements for company officers, large and long-lasting reserves being withheld, etc. The only other game in town for setting up online card payments reasonably quickly and easily at that time was PayPal, which had a reputation somewhere between Satan and the devil even then.
Of course none of this is unique today, and there are now many other services available for taking payments via card or many other methods. But in those days, it truly was a game-changer. As much as I criticise Stripe for its more recent failures, I also give credit where it's due: many small businesses, including at least one of my own, would not have gotten off the ground as early as they did without Stripe.