Thomas Tuchel
Sacked by Dortmund
Sacked by PSG
Sacked by Chelsea
Sacked by Bayern Munich
All managers are sacked eventually, and a lot of those sackings are not his fault:
Dortmund: fell out with the owners because they sold his three best players in one summer and didn't replace them; not results based.
PSG: Probably deservedly sacked with them trailing second in a league they're expected to win every year, but before that won the league and made a CL final, which no PSG manager achieved before or since.
Chelsea: I don't understand anyone who thinks this sacking was his fault. Won the CL when Chelsea were a huge underdog, they next season had to deal with the ownership changeover when Abramovic was sanctioned, and then sacked by Bohley at the first opportunity. What has followed is Chelsea's worst two years in the past two decades.
Bayern: hasn't actually been sacked yet, could still win the CL, and lost tye league to a record-breaking side, with the same points per game average that won the league the three previous seasons.
There are legitimate reasons to be cautious about Tuchel, but "sacked everywhere he's been" is really not one of them. You know who else has been sacked by Bayern, PSG abd Chelsea? Carlo Ancelotti.