ויחי קאפיטל נ פסוק ט”ו: וַיִּרְא֤וּ אֲחֵֽי־יוֹסֵף֙ כִּי־מֵ֣ת אֲבִיהֶ֔ם וַיֹּ֣אמְר֔וּ ל֥וּ יִשְׂטְמֵ֖נוּ יוֹסֵ֑ף וְהָשֵׁ֤ב יָשִׁיב֙ לָ֔נוּ אֵ֚ת כׇּל־הָ֣רָעָ֔ה אֲשֶׁ֥ר גָּמַ֖לְנוּ אֹתֽוֹ׃
It’s a mefureshe pasuk in the Torah that Yaakov Avinu meis. You cannot argue on a pasuk in the Torah. The Gemara is an agadata.
A) Agadata doesn’t mean it is false, it means we must look in the meforshim to understand what it means.
B) Many meforshim explain יעקב לא מת spiritually, others explain it physically.
C) When you have a seeming question on a Gemara or Rishon, you don’t need to disregard the vort. You can just ask. Maybe you’ll get an answer, maybe not.
Rashi/Rif/Etz Yosef/Iyun Yaakov[/Artscroll] definitely knew of this posuk, yet said what they said.
D) Your exellent question stands even if you learn יעקב לא מת spiritually: The fact is that Gemara calls Yaakov לא מת, and Rashi on Chumash (and Tosfos in Gemara) proves it from the fact that the posuk doesn’t use the word מיתה regarding Yaakov, so how can it say מת אביהם!?
E) Ramban (who doesn’t necessarily interpret the Gemara physically) is bothered by the same question as you!
He answers:
ויגוע ויאסף. ומיתה לא נאמרה בו, ואמרו רבותינו יעקב אבינו לא מת, לשון רש”י. ולדעת רבותינו, הרי יעקב הזכיר מיתה בעצמו הנה אנכי מת והיה אלקים עמכם. ואולי לא ידע הוא בנפשו, או שלא רצה לתת כבוד לשמו. וכן ויראו אחי יוסף כי מת אביהם, כי להם מת הוא, או שלא ידעו הם בזה כלל.
“AND HE EXPIRED, AND WAS GATHERED TO HIS PEOPLE. But the word “death” is not mentioned in his case. Our Rabbis therefore said, “Jacob, our father, did not die.” This is the language of Rashi.
Now according to this opinion of our Rabbis, the difficulty arises: Jacob applied the term “death” to himself, as it is written, “Behold, I die, but G-d shall be with you!” Now perhaps he did not know it himself, or it may be that he did not wish to pay honor to himself.
Similarly, with respect to the verse, “And when Joseph’s brethren saw that their father was dead,” we must say that to them he was dead, or it may be that they did not at all know of this.”
In other words, the brothers “saw that there father died” because that is indeed what THEY SAW!
As Rashi write on Gemara, they buried him because TO THEM he seemed dead. But really, he was alive.
This also fits with Rashi’s pirush in Chumash on כי מת אביהם, that they FELT their father’s death because of how Yosef was treating them.
This has nothing to do with if Yaakov is truly alive, rather with the perception of the brothers.
Philosopher, in general, maybe try asking instead of attacking.