That is 150% not true. If you have evidence otherwise, please share it.
There are many bosses that an Ochain Paladin can hold for quite a long time and tp rarely since we can suppress so many hits to 0 via phalanx and the stoneskin granted from solace. On weaker hitting bosses, phalanx makes that stoneskin last several hits and whm's can keep feeding it.
Erinys, Amphitere in Reisenjima, is an NM with a ridiculous TP move where TP fed to him is absolutely critical to manage.
There are "bosses" like the cactus (little Rei T1) that I definitely do everything I can to slow his TP build, which is why we can have several kills where he never gets a tp move off.
You will absolutely notice things TPing much faster if you're hitting them with several melee. A Blue Mage feeds TP much faster than a DNC or NIN (the cumulative effect of so many strikes), even though all three jobs can and do wear much of the same gear and TP at similar rates.
But yes, some bosses do absolutely have have Regain, perhaps Save TP and sometimes Store TP.
Bingo...
Something to think about: Even though GEO debuffs are un-resistable and have potentially REALLY high debuff values, when was the last time you saw someone use something like Indi-Paralyze for group content? ^^;; Increasing macc alone will make us feel better about using them, but will probably need some further adjustments before they become important again outside of gimmick fights like Maju.
Absolutely, a GEO would never use paralyze, because there are so many more useful spells and one of geo's mechanical disadvantages is that it can only do 2.5 buffs/debuffs. Even if you had 3 GEOs, there are almost always going to be 9 better geo spells than Paralyze/Slow/Acc-down