The pandemic.
When that happened, everything changed. Well, that's in my case but I bet it is for others too.
I am a poker player physically, I love playing with strangers who later on became my friends too. Still, when we sit at one table we become competitive again and there's no clue that we are friends. It became like a sport to me and it became my habit to go to that place weekly there are even times I cannot wait for my day off and will go there on weekdays just to satisfy my urge to play.
When the pandemic hit, the place closed down, and even now that it is open again I have not visited it again. I am kind of afraid that different people will be there and I might get shy to start playing again.
Then, I bumped into online gambling sites although I have known them before. i.e. Yolodice, Bitvest, 777, and more. That changed everything because I can satisfy my urge to gamble now by just opening my computer and it's a perk to me because I am also working at home. I don't even need to go outside to gamble and that's what happened for the last 3-4 years if my memory is correct.

I think the ease of access is the main reason why a gambler would just stay at home. You can even do it in your smartphone before going to bed which is a great feature.