One can do all kinds of stuff and get away with it.
The #1 job is to be safe. This needs instrument skills, and a suitably equipped plane. Note that one can be legal VFR yet need to be a good instrument pilot e.g. 3000m vis, summer haze, over the sea. No horizon; it's like in a fishbowl. Night flight (on a real night) is also 100% instrument flight; Kennedy Jr found out the hard way.
The #2 job is to not get into trouble. This needs good knowledge of weather planning e.g. no good turning up above Biarritz at FL100, when the place is OVC002 and has been for days, and call up "G-XXXX inbound" off a VFR flight plan
Anyway, airports in CAS (which is the majority of European airports with Customs i.e. those one is going to be flying to from the UK) all have VFR minima, ~ 1200-1500ft min cloudbases. None of the UK business of departing say Goodwood "VFR" under OVC005
There are specific "VFR" arrival tricks for coastal airports in plausible VFR conditions e.g. OVC015, from a flight which is above a solid thick overcast (basically, you descend offshore and break cloud
OCAS, before calling up the airport, and then no questions asked = no lies told) but you can't do that in Switzerland
Enroute, it is not an issue. It's funny sometimes to realise that with the IR I fly the same way I used to fly VFR in the past. VMC on top. But now I can cross the Alps at FL160 or whatever; previously it would be FL129 because Zurich would not let me into their precious (and totally empty) Class C with a FL130 base. Why do ATC care about VFR transits when there is nothing there? That's the big question... and it's a big part of why pilots sweat to get the IR. It gets ATC working for you (as a default position), not against you (as a default position in so many places).