Understanding Society User Support

I am aiming to look at the impact of residential age structure on a range of health and well being outcomes by linking official data produced for lower super output areas, from the ONS, with information on individuals from Understanding Society using Understanding Society: Waves 1-9, 2009-2018: Census 2011 Lower Layer Super Output Areas dataset (SN 7248) to link these data. My question to you is whether I would need to use a multi-level model. On the one hand the residential level measures are recorded at a higher level, on the other hand there are around 50,000 of these residential areas in the country and Understanding Society has around 40,000 households, therefore it is unlikely that more than a couple of households would be clustered within any single residential area. My understanding of multi-level modelling is that it is necessary to take account of the fact that cases which are clustered in areas/organisations, etc., are not independent of each other given that they share the same area. However, given that it is unlikely that there will be many cases clustered in any one of these residential areas would it be necessary to use this? I have reviewed a number of papers who have conducted similar studies and some have used MLM whilst others, e.g. Area deprivation, perceived neighbourhood cohesion and mental health at older ages: A cross lagged analysis of UK longitudinal data https://www.sciencedirect.com/science/article/pii/S1353829220304238. Any suggestions/ideas/advice would be most welcome.