BTC conferences make no sense.

The creatives should meet for workshops and the users, for whom the FOSS is made, are called upon to pay for the events, to finance them. Then on top of that an incentive, such as a personal voucher code for some hardware, and off you go. And, of course, the events are live-streamed. All good.

As the circle of participants is much smaller, the locations are also smaller and therefore the costs are lower. In addition, some users may have enough space (farm in the countryside, etc.) 

The space has to nurture and care for the devs.

False incentives (earning money with the conference, etc.) are off the table.

 

 BTC conferences are demanded by the market participants and thus they make sense. Of course your vision is also an option, but it is not the only option. People have diverse needs.