dumb logic. Thanos about to have all the Infinity Stones and you want the heroes depowered
There's nothing inherently wrong or illogical with heroes being vastly inferior in "power" to the primary villain. In fact, it's compelling on it's face, especially if it means having to find a solution beyond "powering up" to defeat him.
In storytelling it usually means exploiting other weaknesses in the villain, like their hubris, or other blind spots that are revealed as they wreck havoc. I'd prefer the heroes to get their asses handed to them by anyone wielding these gems, since those stones have been built up by dozens of films like they are the end all, be all to power in this universe. Having the heroes be "stronger" wouldn't have any effect against someone who is the universe's most powerful being anyway.
I'm bored of big CGI tornado light firework battles at the end where the most powerfullest power overpowers the powerful powers.
I'm unconvinced that Infinity Wars will rise above that, especially after seeing Guardians 2, but they did it with Dr. Strange, and introducing time manipulation, reality warping, and other physics breaking elements at least gives them plausible ways to beat someone more powerful than them. Time will tell if that happens or if it'll just be a power up.