They are indeed loathsome, both individually and, especially, collectively, but I don't see that there's much that could be quickly or easily done to get rid. Getting rid of their constitutional role would, Brexit style, take up a stupifying amount of decision-making bandwidth in return for limited benefits, and clipping their wings financially would be near-impossible given how much of their wealth is technically 'private' [though of course in terms of work the family has done nothing other than royaling going back some thirty-odd generations - all of their wealth is the pocketed proceeds of past royalling].
The best and simplest things we could do would all be small fairly token changes , starting with immediately end all bowing, curtseying etc [make them punishable by imprisonment in the tower, if needs be].
'Prince' and 'princess' could become titles bestowed only on the children of monarchs or of senior royals in the direct line of succession, and could become something that is given up on [say] a 21st birthday, so e.g. Prince Andrew could have become plain old Andrew Windsor at some point in the early 80s. It'd IMO somehow have been far less insulting to us as taxpayers and 'subjects' for plain old Andrew Wilson to be using mummy's cash to hightail it round the globe with scum like Epstein than it was for a guy who we're supposed to call "your highness" or "your grace" or whatever other nonsense it is.
Financial scrutiny could be increased to strengthen the presumption that royals will pay for their own stuff - as noted above, there's so much 'private' wealth sloshing around the family that they'll remain impossibly rich for the foreseeable future, but allowances could be trimmed to the point that it's unlikely that yet more land and property etc being added to the pile.