At the end of every month, banks send out statements so importing all transactions aren't necessary to keep track of one's overall financial standing.
Banks do make mistakes but extremely rarely that it's not worth wanting to import all transactions in the off chance that you'll catch a mistake. Retailers can make mistakes like double charge you but again those are rare and you can take a quick look at your statements to find them usually.
Keeping track of individual transactions are important to be able to figure out where the money is going in general but this doesn't require keeping track of 'every' transaction. Just the ones that make up the biggest percentage of the total money spent. They are usually easy to spot on the bank/creditcard statements.
One doesn't even have to be perfectly accurate to gain from inspecting statements either. You spent $834.56 for new tires? You can enter that as $850 and it's fine.
Sure, there might be cases where the total is split more or less evenly across several small transactions and that can be handled similarly to the above.
Knowing where the money is going isn't terribly useful actually unless there are a lot of frivolous spendings. It usually comes down to "you are not making enough money" or "the lifestyle you desire is too expensive for your current income". No app can fix either of these, other than point out the obvious problem. Most personal finance blogs end up leaning towards "how to earn more" because that's more important than keeping track of your transactions or budgeting.