It was bad timing for Jojo wise, unfortunately.
By the time we got Jojo in the UK, the US/Australia got Jojo Part 4 and 5.
One Piece case is mainly due to recent sets released at the time where DVD format demand was nearly non-existent outside of MHA and Dragon Ball.
Boruto was dead on arrival, especially in the UK.
Poor fanfare combined with low ratings on social media sites leads to poor sales.
It was Manga's biggest shounen flop alongside Raidant and Jojo.
Compare to the Naruto franchise which was a big seller (despite how crappy their releases were looking back)