Question

Good week, Rabbi,
In tractate Hullin 6b it says:
“Rabbi Yehoshua ben Zeruz, the son-in-law of Rabbi Meir, testified before Rabbi that Rabbi Meir ate a leaf of a vegetable in Beit She’an, and on that basis Rabbi permitted all of Beit She’an. His brothers and his father’s household gathered against him and said to him: A place where your fathers and your fathers’ fathers practiced prohibition, will you practice permission there? He expounded to them this verse: ‘And he broke in pieces the bronze serpent that Moses had made, for until those days the children of Israel had been burning incense to it; and he called it Nehushtan.’ Is it possible that Asa came and did not destroy it, that Jehoshaphat came and did not destroy it? But surely Asa and Jehoshaphat destroyed all the idolatry in the world! Rather, his fathers left him a place in which to distinguish himself; so too, my fathers left me a place in which to distinguish myself. From here we learn that when a Torah scholar states a point of Jewish law, one does not push him aside.”
What lessons, in your opinion, can be drawn from this story, and in particular what lessons, in your opinion, are there regarding the status of a halakhic custom?
Seemingly, as I understand it, from what is said in Hullin one can learn that the status of halakhic custom is not all that binding, and where we have a reason to change a halakhic custom, we should do so—whether changing it leniently or stringently. Even so, the halakhic decisors of our day, and even those of a few centuries ago, seem to me to have given very great weight to halakhic custom, and only where they had very good reasons to change it did they change the halakhic custom—and even then usually in the direction of stringency. But to change a halakhic custom leniently, for that you practically need a voice from Heaven.
For example, the Beit Yosef wrote in his introduction as follows:
“And if in some lands they practiced prohibition regarding certain matters, even if we decide the opposite, they should retain their custom, for they have already accepted upon themselves the words of the sage who prohibited it, and they are forbidden to practice leniency, as is stated in the chapter ‘A Place Where They Practiced’ (Pesahim 51a).”
Although perhaps one could understand the Beit Yosef to mean that the whole obligation to continue maintaining the prohibitive custom stems from the concern that ignoramuses will come to permit outright prohibitions when they see a learned person acting leniently in something that is established for them as forbidden (as brought in Pesahim 51a), whereas in a place where that concern does not exist, it is permissible to abandon the custom of prohibition.
Best regards,