Why do movie producers tell us a amazing movie scene/movie scenes were cut but won't let us watch it?

[Mystic]

Like you got 45 minutes of Thanos looking for the power stone but you cut it and won't let us watch it smh. Like let us pay $10 to see it so you can recoup what you spent making said scene smh

 

[AnonymityX1000]

I'm sure the scene required a lot of FX that were not completed. It's an unfinished product and I guess they don't want to give up info on how the sausage is made. Or a poor representation being highly criticized.