The trouble is:
There will always be people who insist that those 'lesser' than they (by their own evaluation) deserve no rights. This should be rectified, where possible, by legislation.
There will always be people who recognise the rights of others but claim their own rights trump others'. This should be adjudicated, as fairly as possible, by law.
There will always be those who defend their rights without accepting their responsibilities. They should be made to accept them, as far as possible, by law.
Which leaves you relying on a legal system to make all the selfish bastards act like functioning members of a functional society. The law, though, has its own agendas and they can be pretty selfish too.

Since we don't live in an ideal world, I empathise with those who realistically don't have any opportunity for sexual experience unless they are assisted. The usual way of such things is for the person of compromised opportunities to pay to get their needs met - paying for company, for example, as well as to have their toilet needs attended and so forth.
If we cannot envisage a paid-for sex service without exploitation, how do we balance that issue against the limitations of the person who can't have sex (or go to the toilet, etc) without hiring someone to assist?
I would like to think there are people who provide this service honestly and - at least - no less willingly than the toileting assistant. The websites I looked (very briefly) at seemed to suggest there are.
But I just ... don't ... know.