I have not used Meson, but other build environments (e.g. Make) don't interact as well with IDEs as CMake does (with the exception of premake, which is mostly dead.
No, that's the wrong question and one that's only purpose is to deflect attention from its shortcomings.
All build tools need tooling because if they are adequately integrated into development workflows they are transparent and easy to use. Cmake meets that requirement, and until other alternative build systems do then they will always be far more complicated.
Another poster has explained the IDE support is about IDEs being able to parse CMake files, and I can say that back in the day before CMake IDEs would parse the C/C++ directly using a compiler to output an abstract syntax tree that they would use. So for example Eclipse has this notion of "Build configurations" which allows you to control how this parsing occurs and which files the parser considers valid and what symbols are predefined. Which is IDE support very much like you're looking for from CMake. I worked with it for several years at my last job to provide support for other engineers working with a Make-based build system.
C++ really benefits from it. ctrl+click on a symbol is much more sane than (re)teaching Argument Dependent Lookup rules to all of the engineers in your organization.
It's good to have tooling and IDEs for CMake because CMake is complicated and hand-editing the files is very tedious. But if Meson eliminates the tedium of CMake by providing you with different abstractions then you don't actually need the IDEs or tooling.