Who do you think will take responsibility for Brexit?
where did you get your information exactly? a section of the high quality British press?
there's your answer
remain had almost the entire British establishment behind it: the government, the civil service, all large political parties, most of the media, the City and all other industry. these groups mostly had their own self-interested reasons for wanting to remain ($$$ at risk dependent on the result)
leave had Aaron Banks, Farage and maybe a dozen other prats. they also had their own self-interested reasons for wanting to leave ($$$ at risk dependent on the result)
in terms of access to resources, remain absolutely dominated leave by several orders of magnitude
this was one of the reasons it was such a shocking result
> That the economy as a whole shrunk doesn't seem to have impacted them much
it didn't shrink as a whole, it's larger than it was in 2016
and since 2019 it's grown more than its France and Germany (peer nations), in both absolute and relative terms