If that's really the case then Silicon Valley salaries have gone through the floor recently. That would be considered an insulting salary for a developer in London, in GBP.
If you search for web designer jobs in the UK on Indeed, most jobs are in the £25k to £30k range, with a slightly smaller selection between £30k and £35k.
London may be in a class of its own, but elsewhere in the UK £35k is considered decent money.
Don't disagree about £35k being decent in the UK - easy to take for granted how well paid the tech industry is.
That said, a "Web designer" role and a "Developer" role are two completely different things. £35k is about right for a decent web designer salary; but for a developer, that's more of junior to mid-level role, even outside of London.
(Good) developer jobs tend not to make it job sites like Indeed. I'd expect a developer job somewhere other than a small agency to be starting at ~£30k anywhere in the country, and £35k in London. In London a half-decent developer can make ~£50k easily, and much more than that if they're good, or willing to do contract work.
