Is there a way to reverse this and de-commodify land as a speculative tool,
and still finance of big ticket items such as, childcare, education and elderly care, let alone families helping their children with house deposits. (Hetherington Ryan-Collins, Shrubsole,)?

Yes, but we have to look at the last great social (rather than financial) revolution, namely the Attlee Government of 1945 for clues. ( Kynaston, Keynes, Loach, Mass Observation)

Research

In my research into the affordability of housing thus far, specifically for the under 35’s (with no parental assets to call upon), there seems to be a lot of explanation as to how and why we are where we are, but very few real solutions, and the ones that are being promoted are small (Ryan-Collins, Lloyd, Shrubsole, Werner), too distant from the public gaze, and often complicated to appease large donors ie the large construction companies holding huge swaths of land, which again leads to possible and actual fraud from local to national government MP’s and officials (Lonergan, Kelton), This also applies to legislation concerning the finacialied debt industry as we saw in the 1980’s.

The last real revolution in housing was born out of a report by William Beveridge  into the mistakes of the post 1929 crash that led to the 1930’s depression, also the broken promises of post  WW1 1918 ‘homes for fit for heroes‘ campaign to tackle the industrial slum houses of the Victorian period. (Beveridge)

The five giants that the author of the report highlighted were: illness, ignorance, disease, squalor, and want. As we know, Clement Attlee’s government of 1945-51 tackled these in a radical manner, funded out of a US dollar ( fixed rate to gold, Bretton Woods) linked currency, which was a huge problem as it meant in a sense the government weren’t really the true issuer of their own currency, as later born out with IMF loans and devaluations of the pound, but they went ahead anyway. 

Today we don’t have these constraints ( Fiat currency 1973).(Beveridge, Keynes)
The issues we have at present, along with housing (due to the decisions of the past 50 years inspired by Hayek and Greenspan) are;

• No affordable childcare,
• No free higher education/apprenticeships,
• No unemployment related to national average income,
• No elderly provision.
  

With projected long term slow growth in the UK economy, (after a possible short rise post Covid) along with long term Brexit issues, (which at present are all negative, otherwise the right wing MSM would be shouting from the rooftops, note the silence), then in reality there is little or no long term growth and even a possible Japanese style 1990’s stagnation for 30 years.