How have people living in their own home "benefited from" house price inflation? They live in the home - so no cash available from it. (Equity release is known to be a rip-off in many circumstances).
And thanks to house price inflation, many are isolated (at a vulnerable age - when especially needing family support). Because their children and grandchildren have been socially cleansed out of the area, and/or can't afford their own home - which is a source of distress for their parents, most of whom can't afford to help their DC buy a home.
And no they can't all just downsize. Even if well enough for the massive upheaval of moving, downsizing has been devastating for childless/child free people and only-child families. Might be area dependent but in many parts of the UK, not only is there a lack of 1-2 bedroom homes full-stop, there's far too few suitable for elderly people (or younger disabled people).
And if you mean even more tax on landlords (who are all generations - more than a few in their 20s and 30s), what a disaster for lower income, or even medium income renters, who'll be without any home - because the landlords will just sell up and no that won't mean people on the lowest incomes will be able to get a mortgage to buy. Btw homelessness including substandard temporary accommodation costs the NHS loads - because bad or insecure housing harms health.
I do, however, agree with slightly increased income tax - with the caveat it's not misspent.
Also more council housing across the UK asap, including 1 and 2 bedroom homes, and homes suitable for elderly (and younger disabled). More council homes (that are well-maintained) would save the NHS loads.