But you have yet to provide a single source for such a bold claim.
I gave two – R’ Chaim and Mesorah. But from a halacha lemaisa perspective, as long as there are legitimate poskim/gedolim who hold (it’s ok) not to wear techeiles, there is halachic grounds not to, and therefore Rabbeinu Yona does not apply.
Furthermore, the Radzyner Rebbe says that this Rabbeinu Yona is SPECIFICALLY talking about Techeiles, considering that there is no other mitzva that was not done by your ancestors and city.
1- Is he the only pshat given in Rabbeinu Yona?
2- Even if yes, it is a valid argument that he wrote it almost 1000 years ago, and there are plenty of differences betw. now and then. (And you have no basis to invent that “but mesora is mesora!! what he held then he would hold now” etc, etc.)