I suspect its rather more than half?
As the article says, it's 41 out of 42 in Spain and they have still gone ahead with it.
Plenty of others sports as well rely of sponsorship from betting companies.
Would be a hammer blow to multiple sports in this country if any ban were to come in. TV adverts should be banned but nobody realistically gets a gambling addiction due to name on a shirt or title of an event.
Similar argument was made around banning tobacco and alcohol sponsorship IIRC. But I agree that TV adverts do far more harm than naming rights etc. Is there though also a more insidious element of betting companies having influence on clubs/leagues via sponsorship as well?