A modern programming language that makes developers happier.

kotlinlang

I think they target completely different use cases and hardly could be compared

Bazel about efficiency of build but sacrifice easy of configuration a lot, enforces heavy modularisation to be efficient, often requires dedicated build engineer, until recently no official IDE support, but even new one is quite basic, the main goal to load project in IDE
Amper is opposite to this in all regard as I see, prioritise super simple config for newcomers, pre-configured as much as possible, the main goal is to have great IDE support in terms of configuration assistance and to make IDE integration efficient (so it doesn't require long config phase)

if Amper suited for large projects on current stage is a big question, maybe it does, but I would like to see if anyone actually tried to do this work

Bazel targets only exclusively large/very large projects for small/medium sized ones, it's a huge overkill imo