Is it the application or implementation?

With most things, it's easy to see where an issue is. There's only one way to build a car or a mobile phone, for example.

With other things, such as software, it's not as clear.

There are usually multiple ways to achieve the same result, but not all implementations are equal.

It's important to understand if an issue is caused by the software itself or how it's been implemented.

Some approaches may be quicker, better for end-user experience or more performant.

Each has its own advantages and disadvantages.

What was the correct solution then may not be the best one now.

Priorities may have changed or new approaches could be available.

You know more now about the problem that's being solved than you did at the time.

One of the original discarded solutions could now be the best option, or a new option that wasn't previously available that solves the problem in a different way.

The software may be capable of achieving what you want - it may just need to be configured in a different way.