I think we can also blame the poor exchange rate, Brexit and the cost of accommodation in London.
A serviceable 1 bed apartment should be possible for equivalent 50-60 per night, so that's barely 30 mins work daily.
Girls can make plenty of money even at 100-150 ph. The dearth is more down to the smart SPs have made their bank and gone home to buy their homes and launch their regular businesses leaving us with mostly those who don't know how to provide a desirable service to maximise returns or save their money.
This is compounded by the influx of several nationalities of SPs who culturally aren't suitable for a properous approach to this line of work.
Further, as mentioned, we have a new generation of sex workers (sorry "sugar babies") with millenial delusions of entitlement who all expect IG lifestyles and influencer kudos for being vacuous incompetents who throw a strop if you don't appreciate how special they are.