I wasn't aware of home hi-fi but British gear for musicians was widespread when I was growing up (Marshall, Vox, etc).

I was specifically thinking of the components my father got through the Army PX in the 60s and the hi-fi gear I would see at some friends' houses in the decades that followed ... sometimes tech that never really took hold, such as reel-to-reel audio. Most of it was Japanese, and sometimes German.

I still have a pair of his 1967 Sansui speakers in the basement (one with a blown woofer, unfortunately) and a working Yamaha natural sound receiver sitting next to my desk from about a decade later.

Wharfedale (1920s) and Cambridge Audio (1960s) were there, and are still making great home hifi.

British music of the 60s and 70s was pretty great to listen to on that hifi.