When a digital project fails, the first suspect is the technical team. In our experience most failed projects were built perfectly well. The problem is that the right thing was not built.
You can see the warning sign in the first meeting. If you ask what the project should change and the answer is only "make our site more modern" or "look more professional", the project has not been defined yet.
A useful answer always contains a verb and a number. "We want the sales team to stop chasing delivery status." "We want half of orders placed without a phone call." Those can be checked later. Adjectives cannot.
The second common cause is scope that grows quietly during the project. Each addition is reasonable on its own; together they derail it. The fix is simple and unpopular: the list of things you are deliberately not building has to be written and signed at the start.
The third is treating launch day as the finish line. The site ships, the invoice goes out, the team leaves. Six months later nobody knows whether it worked, because nobody was ever going to measure.
In one sentence, a project whose success criteria were not written before it started cannot succeed because nobody has defined success.