People who are obviously not resident in the UK, and who are bringing in items in quantities for personal use, don't have problems.

​​​​​Questions arise if you:
Live in the UK and HMRC think you are importing the items permanently.
Have more items than necessary - one Rolex is for telling the time, five Rolexes is not. One iPhone X is for you. Five iPhone X are clearly unlikely to all leave the country with you. One Hermes bag is nice. Two different Hermes bags is great for you. Ten Hermes bags of the same model in a range of colours is taking the piss.
Are carrying a lot of cash, especially more than £10000 and do not declare it.

etc,etc.

You can see how that tends to clearly divide the innocent and the suspicious. So bringing in personal amounts of gear is not a problem.