As others said- log I and start riding earlier. Go to a world and just sit sit if you want- the 'joint icon will then pop up.
I fully agree- it would be nice to join directly from the main screen. I can't think of why that shouldn't be an option.
Last year I finally ditched my laptop as it would take 10-30 minutes to connect and then also sometimes drop the ant+ signal right before an event. I kissed countless events because it would take forever to load.
AppleTV changed that. Zwift is what's used on it 97% of the time, but its been worth it. Loading is immediate, the signal has always been perfect, and it's fewer cables to project onto a TV screen compared to my old setup.