London's annual Serpentine Pavilion should abandon its commitment to giving overseas architects their first English commission and instead prioritise experimental, purposeful architecture, writes Phineas Harper.

It's hard to pinpoint exactly when the Serpentine Pavilions got dull. Another structure has just opened on the lawn of J Grey West's 1934 tea-rooms-turned-gallery, but does the series still mean anything" Over two decades in, can west London's pavilions programme still move audiences, or is the annual commission running on the fumes of nostalgia for lost glory days"
This year's pavilion, the 23rd in the series, has been designed by South Korean practice Mass Studies. It comprises five roughly triangular black-stained timber portals forming a star around a circular void with cement paving throughout. The last great Serpentine Pavilion was 2014
Each portal has a slightly different function, paired with a slightly different facade. There's a wide, sittable portal with translucent pink walls; a tall portal with orange mesh walls; an obligatory coffee portal with tinted glass walls, and so on.
One portal (with black timber walls) houses a "library of unread books" where visitors leaf through donated volumes before wandering off. "It's not really clear what this is," I overhear an invigilator remarking. "You can donate books but can't take them away ? that concept doesn't make sense to a lot of people. There is also nowhere to sit. The...