Other people's behaviour acts as a cue for what to do, buy, or believe.
More quotesMost friction is crap. Some friction is a seat belt.
The hard part is knowing which one has been dumped into the journey. Illegible forms, tiny type and needless confirmation screens usually create abandonment, not wisdom. But effortless momentum is dangerous when the next click sends £10,000, deletes a year of work or accepts a contract nobody has read. A bank asking for one extra confirmation before paying a new recipient is not “ruining conversion”. A destructive command requiring the project name is not bad UX. A checklist that interrupts an expert for ten seconds may be the only thing stopping routine from becoming complacency.
The font experiment is useful because awkwardness interrupted an automatic answer. It is not a licence to publish important information in typographic porridge and congratulate ourselves on making readers think. Make the information clear. Put the pause at the consequential action.
I separate comprehension friction from decision friction. The first makes it harder to understand what is happening; remove it. The second creates a moment to notice what is about to happen; use it sparingly, proportionately and where mistakes are costly. “Frictionless” is a daft universal ambition. Brakes are friction. Doors are friction. So is the confirm button that saves someone from a catastrophic mistake. Good design is not always faster. Sometimes it is just slow enough.