We have it already with samadhi, which has the spectrum of the jhanas. You could also take pamujja as a pre-step to the first Jhana (see Practices leading to samādhi)
The texts are not particularly clear about how exactly to achieve jhana (and maybe this question indeed evades an ostentatious definition) but they are conceptually clear and consistent. It is what it is, and experience shows that most people’s meditation experiences are not life-altering or sustainably liberating in a dhamma sense. Why then to ‘lower the bar’ and give even more people the impression that they experienced something profound when what takes place in most cases is inconsequential neurological fireworks? Especially beginners tend to get overexcited about their experiences anyway, so it makes sense from a teaching perspective to rather err on the careful side.