streaming shows are a little different from old network shows, there are no residuals or anything offered so they gotta pony up more money upfront, but Disney (netflix, HBO Max, etc) don't have to ever pay out again. They usually don't do DVD releases either, and keep all the international rights as well.
So while a star might have been paid less for say CSI Miami, the entire above the line cast and crew got paid for decades, as the show got resold over and over. All that kinda money gets bundled more upfront with these type of shows. For example the cast of Friends makes $20m/year EACH still to this day, due to the resell value of the show. That won't happen with WandaVision, Mandalorian, etc. Disney gets every penny of the monthly sub fees and doesn't have to share any of it, just pay for initial production.
The season finale isn't a clip show, is it? That thing posted above is just a trailer for the finale? I didn't watch it.
Disney+ is at 94m subs right now and expects to hit 260m subs by 2024. Thats $8.4b/year in sub revenue right now, and expected $31 BILLION in sub fees within 4 years. The numbers dwarf previous Hollywood box offices, and they just have to pump out content to keep people subbed.