Based on the following HMRC guidance: https://www.gov.uk/government/publications/reporting-rules-for-digital-platforms/reporting-rules-for-digital-platforms most people will be unaffected by the new regulations. As noted it is part of an international (OECD) drive to address tax evasion.
Looks like the measure is intended to catch "businesses" that use digital platforms to generate revenues but don't declare them. It looks like any tax burden would be subject to corporation tax or income tax in the case of a sole trader.
Having said that, there are instances where Capital Gains Tax or Inheritance Tax still might apply, as mentioned earlier.
At this (early) stage, HMRC have only estimated the cost (£36mm pa for the 24 FTE needed to oversee it), with no estimate of the additional tax revenue it might generate.
Seems pretty much unpoliceable unless there are very clear cut instances of individuals not declaring the income, probably more likely on platforms like AirBnB?