If Potter said we destroy managers' CVs, then he proved how shitty his judgement is and why he's now managing Spam.
Our last managers have gone on to manage PSG, Roma, Napoli, Chelsea, etc. They've all won trophies and competed in the CL at their next stops. Potter, again, is at fucking Spam.
Levy is a cunt, but there's a handful of jobs on the planet better than Tottenham - even with Levy. And the number of times those jobs come open, and that opening aligns with the moment a manager is peaking at a lesser club and therefore attractive, is very few and far between.
Most of those jobs are very unlikely to come open in the next 18 months. Frank is well paid, and seems happy. Iraola is making 1/5th of what he would make at Spurs.
Gambling that you'll still be a hot name 24-30 months from now when one of those handful of jobs better than Spurs comes open is a big risk. Iraola be sacrificing £4M next season.
None of the jobs that are arguably better than Spurs in the PL (Liverpool, Chelsea, City, United), La Liga (Madrid, Barcelona, Atletico), Serie A (Juventus, Inter), Bundesliga (Bayern), or Ligue 1 (PSG) look like they'll be open in the next 24 months.
So then you're looking at clubs in equivalent situations. Milan, Roma, Lyon, Everton, Dortmund, etc. Clubs where winning the EL is probably the most success you'll be able to achieve due to the financial position of the club in comparison to their direct league and European competition. Now, maybe not having to deal with Levy is worth managing one of those clubs instead. But none of those clubs are more (or less) likely a springboard to greater success than Spurs.