Correction: it's illegal to bike when very drunk. In the moderately drunk range, German law is surprisingly reasonable in acknowledging that drunk driving would have been much worse.
Germany has a BAC threshold where acting stupid while being slightly tipsy is considered worse than acting stupid while being perfectly sober and that is indeed quite low (0.3). This entry level threshold does not distinguish between car and bike at all (pedestrians are fine). That level basically means "go for it, but at your own risk, and if someone else fucks up, you are partially responsible because might very well have have saved them if you had not been drinking".
But the "folk wisdom" of drivers completely ignores that threshold and only considers the next stage relevant (BAC 0.5+, used to be 0.8) and this only applies to motor vehicles. For cyclists, the next threshold does not happen before BAC 1.6. I suppose that wouldn't exactly be allowed in the UK either?
> Not in Sweden and we have less accidents than Germany.
I don't think you got the memo where everyone seems to think getting blind drunk and then getting on an electric scooter is totally ok "in Sweden".
I've had a few near-misses myself with crazy drunk riders on pedestrian streets in central Stockholm; I once interviewed a job-candidate with a cut-up face who laughingly told us he'd crashed a scooter with two(!) friends on the back after a drink night; a friend of mine smashed their hip after a night drinking and then jumping on a scooter.
The rules may be there. The actual reality is different.
You can not be convicted for drunk cycling, but you can still be stopped for recklesness in traffic. Same goes for e-scooters. As long as you do not cause problems there is no legal or social taboo.