Most plans to implement LVT at scale that I've seen include provisions to increase the rate slowly over years and decades, and allow deferred payments for the elderly upon sale or from their estate because yeah, a lot of people made plans to retire based on the present tax regime. Younger people saving for retirement can plan on putting retirement savings into productive assets rather than land speculation. I'm also not entirely clear on why a pension that pays for everything except housing is fine, but providing housing for the elderly is a problematic level of state intervention.