This is a interesting long read on the subject: https://fatnickindustries.com/Blog/2019/07/03/8-bit-showdown...

The NES did get past a million sales in the UK, but a lot of them seem to have been at a cheap price late in its life once the SNES and (more so) the Mega Drive had established a popular market for consoles in the UK.

An indicative fact on consoles vs computers that the article highlights: in 1991, Sonic the Hedgehog on Mega Drive reached #11 in the UK charts on its release, and it was considered a remarkable and unusual achievement for a console game to do so well.