I was doing my research and ended up back where I started, with Zoom Webinars.
Why was I looking for another option at all? Because Zoom is relatively expensive (€90/month).
Demio: For a while I was seriously considering Demio. At €50/month, the price seemed fair. But they had too many technical issues. First the demo video on their site did not play. Then the calendar entry was fixed at one hour. The last straw was that the platform had a bug with Chrome and OBS.
Webinarjam: This sounded interesting at €40/month, but they only do annual. As I don’t expect to offer webinars every month, €470 is rather steep.
GotoMeeting: At €55/month and a good reputation, I sounded like a save choice. Unfortunately, Linux is not supported for the organizer, only attendees.
In addition to the above, I am always concerned about stability and good user experience for the attendees. Small players are always a gamble in this regard. Zoom has everything I need and I used it in the past for webinars. It’s double than what’s on the market, but it feels like good value.