I'm not sure these things are about "big hit of dopamine". It's more about keeping user's attention on screen. And e.g. tiktok repeatedly shows minimally interesting videos, keeping viewer in expectation: how does this video end? would next the next video show?

So it's not about intensity, but quantity and repeatability.

MrBeast videos consists of many short segments each one having some small intrigue and/or delivering a tiny piece of interesting information.

The direct analogy with fracking is that these methods attract attention to things which normally don't warrant user's attention. I.e. normally we have defenses against getting attention stuck on one thing - it quickly becomes boring. But the industry managed to circumvent this by breaking these things into small pieces with tiny story-arcs in them.