If you're OK with locking up your money for 30+ years, sure.
> no property taxes in the UK
That's a bug, not a feature. There's little incentive for people to downsize, which leads to suboptimal use of resources on a societal level. Even if you leave the question of fairness aside ("eight of England's 10 cheapest areas for council tax are in the capital including Kensington & Chelsea, Hammersmith & Fulham, Southwark, Lambeth and Tower Hamlets"), this leads to higher property prices, which negatively impacts you as a first-time buyer.
> I'm looking at $1.8m-2m minimum in SF
You don't have to retire in the Bay Area.
> Most startups in the UK are offering EMI share options
Most startups in the UK pay poorly, so I'm not sure this is a good point. Thanks for letting me know about EMI share options though, I didn't know that!
> you can draw nearly 97.5k in income and pay only 3750 in tax
You can top that. People who have bought property in London 15+ years ago can easily realize a profit of £500-1500k, all tax free -- https://www.gov.uk/government/publications/private-residence... .