It shouldn't be a problem. In science, everything must be tested and proved if you want to know the truth or the effectiveness of an theory. Design is a science, so it can be measured and developed by tests of all kinds, even emotionals.
That's a pretty one-sided statement. One could easily argue the opposite, that good design is an art form, not a science.
Art is a science too. One different thing is that some artists don't care about the facts. Everything can be explained with numbers.
Whereas a design studio with sufficient resources should fare better with a data-driven approach, a sole designer or small team with time and feedback constraints will probably do better with traditional methodology. Traditional methodologies might have certain quack dogmatic rules and processes, but it offers a battle-tested baseline.
I worked at a major tech company where every decision needed to be justified by AB testing. Our design was a series of haphazard guesses made on data that depended on a very brittle data pipeline. Needless to say, nobody thought it was a very good product, but the incredible bureaucracy and people behind the approach made it hard to fight against.