In 3.5, the rule about Taking 10 is that you couldn't be threatened or distracted. It wasn't a matter of time spent, so much as whether you're actively dodging arrows right now.
If 5E had the same rule, then you could reasonably have a professional locksmith with +5 to the check, and they would be able to pick easy (DC 15) locks 100% of the time, even though they would only be able to pick a master (DC 25) lock 5% of the time. The Take 10 rule lets you bypass the inherent issue with Bounded Accuracy, where being able to perform easy tasks reliably means you have an unreasonably good chance at performing incredibly difficult tasks. With Take 10, a professional locksmith could definitely get you back into your car, but wouldn't be particularly likely to break into Fort Knox.
To contrast, simply letting someone re-try forever only exacerbates the problem with Bounded Accuracy. Anyone who stands a reasonable chance at getting you back into your car (+5 on the check, vs DC 15) would definitely be able to break into Fort Knox (DC 25) eventually. In order for that world to make sense, you essentially have to assume that everyone will roll a 20 eventually, and base the DCs on that. If the break DC for a set of manacles is less than 23, then anyone with moderately-decent Strength will be out within two minutes. But then, if you design around that, then it means any average person will have zero chance whatsoever.
In summary, Bounded Accuracy works well in conjunction with Take 10, but it does not work well with unlimited re-tries.