WordPress became this popular precisely because almost anyone can put a site together with a drag & drop editor. That is true, for the first three days. After that come the questions the editor no longer answers.
What tends to happen DIY or with an inexperienced team
The requirements get met by stacking plugins on top of each other. Each one brings a little slowdown, a little risk and a new dependency. The site works as long as nothing changes, but at the first major update it falls apart and nobody can quickly work out what broke. That means days, sometimes weeks with a website that does not work.
What comes down to the design
A website decides within seconds whether it can be taken seriously. That is not a matter of taste but of proportion, spacing, typeface choice and order. Individually these look like details; together they are exactly the difference between looks like a professional made it and looks cheap.
What ends up costing the most
A badly built site is often easier to rebuild than to fix. Which means the saving did not save the cost, it only postponed and doubled it, while the visitors who would have arrived in the meantime went elsewhere.
What we bring to it
In 15 years we have met a lot of companies and a lot of mistakes, so we can spot most dead ends at the drawing board. We know which plugin suits which job, and we also say when custom development is the better answer. We follow the trends, but we do not build in every fashion: the site has to look good and work well two years from now as well.