Why did a famous European coach reject Chelsea's offer?

The transfer market for coaches in European football has started to heat up again. Julian Nagelsmann is currently not showing interest in the option of working at the Chelsea club.
It has emerged that the London club decided to change their head coach following recent unsuccessful results. Chelsea's management ended their partnership with Liam Rosenor after the 0-3 defeat against Brighton and began searching for a new specialist.
According to internal club analysis, Rosenor's lack of experience working with top-tier clubs negatively impacted the team's results. Therefore, the 'aristocrats' aim to attract an experienced and reputable coach who can handle high pressure.
Julian Nagelsmann is seen as one of the candidates who fits these requirements. He gained experience managing a top club by working at Bayern Munich from 2021–2023. However, according to The Telegraph, the 38-year-old specialist does not currently consider this option a priority.
Meanwhile, Nagelsmann's name is also being linked with Manchester United. However, he intends to make a decision about continuing his club career without haste.
It is noted that if Julian Nagelsmann wishes to return to club football, he will only make this decision after the major international competition, the World Cup, which takes place in the summer.
In short, while the search for coaches for European giants continues, Nagelsmann is carefully planning his future. This means his next step will bring even greater resonance.