I got around this, specially around 'planning poker' when I got to be lead in these scenarios that forced you to do it. Whenever there is a discussing on how long something should take, whoever says the least amount, is tasked with the job. After 1-2 of these meetings, amazingly, all estimates started to come back quite higher than before.

I still believe that whoever takes the task, should be the one deciding how long it will take, and only after understanding the scope of the work. Planning poker is the most useless piece of shit I ever seen, and still, it is used all around by idiots. If I am asked to estimate something, I will always give the highest possible value and justify with "I don't know enough about it to estimate". If I am managing and I have a top down force pushing for this, I will always make sure that the stupid process is obvious how fucking broken it is.