As someone who wrote an 2 attendance apps (in PHP and Rails) for my church, and a time-and-attendance app (with a checkin/checkout page) for a previous employer (which I've heard is still being used, many years later), let me say that I think there are 2 things at work here.
First, you can't underestimate the value of software that works EXACTLY like you need it to. At both my church and my job, the software I wrote did something very specific to those organizations, and NOTHING else. At the church, the key was making a great interface on a small device, and various people would use Palm Pilots to quickly and discreetly mark people as having attended. At the job, the key was in making the online form work exactly like the paper sheet that people had been filling out, and then making a single page for the person who did the billing, which had 2 pivot tables for time, one for employee hours, and one for customer project hours. Both systems were very fast, and you could do your thing in seconds.
Second, any T&A system you buy/rent is trying to be all things to all people, and violates the first point, which makes them hard(er) to use, and adds friction to your internal process. I think you'll see the problem if you rephrase your question like this: "I thought general ledger was a solved problem." It was. 40 years ago. And 90% of IT in the 90's was in customizing off-the-shelf systems to work like companies needed them to.
I work for one company, wholly-contracted to another. The first company uses Workday, which I guess is taking over the world now. It's perfectly awful in an expected way. The parent company has just written their own time tracking tool, and it's predictably terrible. It takes several seconds to click through each project number, and there's a lag on entering hours in each day. But, this is what you get when you're stuck in the outsourced, waterfall development mindset from 25 years ago. I expected nothing else. In my opinion, both of these decisions were the opposite of what needed to happen. My small consulting company should have used an internal resource or 2 to roll our own, and the mothership should have subscribed to Workday.